Definition: In this task, you are given a context, a subject, a relation, and many options. Based on the context, from the options select the object entity that has the given relation with the subject. Answer with text (not indexes).
Input: Context: A boot is a type of footwear and a specific type of shoe. Most boots mainly cover the foot and the ankle, while some also cover some part of the lower calf. Some boots extend up the leg, sometimes as far as the knee or even the hip. Most boots have a heel that is clearly distinguishable from the rest of the sole, even if the two are made of one piece. Traditionally made of leather or rubber, modern boots are made from a variety of materials. Boots are worn both for their functionality  protecting the foot and leg from water, extreme cold, mud or hazards (e.g., work boots may protect wearers from chemicals or use a steel toe) or providing additional ankle support for strenuous activities with added traction requirements (e.g., hiking)  and for reasons of style and fashion., The Mediterranean Sea (pronounced ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Southern Europe and Anatolia, on the south by North Africa, and on the east by the Levant. The sea is sometimes considered a part of the Atlantic Ocean, although it is usually identified as a separate body of water., Slovenia, officially the Republic of Slovenia (Slovene: , abbr.: "RS"), is a nation state in southern Central Europe, located at the crossroads of main European cultural and trade routes. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and the Adriatic Sea to the southwest. It covers and has a population of 2.06 million. It is a parliamentary republic and a member of the United Nations, European Union, and NATO. The capital and largest city is Ljubljana., A mediterranean climate or dry summer climate is the climate typical of the lands in the Mediterranean Basin. The lands around the Mediterranean Sea form the largest area where this climate type is found, but it also is found in most of coastal California, in parts of Western and South Australia, in southwestern South Africa, sections of Central Asia, and in central Chile., San Marino, officially the Republic of San Marino, also known as the Most Serene Republic of San Marino, is an enclaved microstate surrounded by Italy, situated on the Italian Peninsula on the northeastern side of the Apennine Mountains. Its size is just over , with a population of 33,562. Its capital is the City of San Marino and its largest city is Dogana. San Marino has the smallest population of all the members of the Council of Europe., Merano or Meran is a town and "comune" in South Tyrol, northern Italy. Generally best known for its spa resorts, it is located within a basin, surrounded by mountains standing up to above sea level, at the entrance to the Passeier Valley and the Vinschgau., France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. Overseas France include French Guiana on the South American continent and several island territories in the Atlantic, Pacific and Indian oceans. France spans and had a total population of almost 67 million people as of January 2017. It is a unitary semi-presidential republic with the capital in Paris, the country's largest city and main cultural and commercial centre. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse and Bordeaux., South Tyrol (German and ), also known by its alternative Italian name Alto Adige, is an autonomous province in northern Italy. It is one of the two autonomous provinces that make up the autonomous region of Trentino-Alto Adige/Südtirol. The province has an area of and a total population of 511,750 inhabitants (31.12.2011). Its capital is the city of Bolzano (German: "Bozen"; Ladin: "Balsan" or "Bulsan").
According to 2014 data based on the 2011 census, 62.3 percent of the population speaks German (Standard German in the written norm and an Austro-Bavarian dialect in the spoken form); 23.4 percent of the population speaks Italian, mainly in and around the two largest cities (Bolzano and Merano); 4.1 percent speaks Ladin, a Rhaeto-Romance language; 10.2% of the population (mainly recent immigrants) speaks another language as first language., A parliamentary republic is a republic that operates under a parliamentary system of government where the executive branch (the government) derives its legitimacy from and is accountable to the legislature (the parliament). There are a number of variations of parliamentary republics. Most have a clear differentiation between the head of government and the head of state, with the head of government holding real power, much like constitutional monarchies. Some have combined the roles of head of state and head of government, much like presidential systems, but with a dependency upon parliamentary power., The Adige is a river with its source in the Alpine province of South Tyrol near the Italian border with Austria and Switzerland. At in length, it is the second longest river in Italy, after the Po river at ., Standard German (, or ) is the standardized variety of the German language used in formal contexts, and for communication between different dialect areas. It is a pluricentric Dachsprache with three codified (or "standardized") specific regional variants: German Standard German, Austrian Standard German and Swiss Standard German., Switzerland, officially the Swiss Confederation, is a federal republic in Europe. It consists of 26 cantons, and the city of Bern is the seat of the federal authorities. 
The country is situated in Western-Central Europe, and is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland is a landlocked country geographically divided between the Alps, the Swiss Plateau and the Jura, spanning an area of . While the Alps occupy the greater part of the territory, the Swiss population of approximately eight million people is concentrated mostly on the plateau, where the largest cities are to be found: among them are the two global cities and economic centres Zürich and Geneva., The euro (sign: €; code: EUR) is the official currency of the eurozone, which consists of 19 of the member states of the European Union: Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia, and Spain. The currency is also officially used by the institutions of the European Union and four other European countries, as well as unilaterally by two others, and is consequently used daily by some 337 million Europeans . Outside of Europe, a number of overseas territories of EU members also use the euro as their currency., Trentino-Alto Adige/Südtirol (; ) is an autonomous region in Northern Italy. Since the 1970s, most legislative and administrative powers have been transferred to the two self-governing provinces that make up the region: Trentino and South Tyrol., Vatican City , officially Vatican City State or the State of Vatican City, is a walled enclave within the city of Rome. With an area of approximately 44 hectares (110 acres), and a population of 842, it is the smallest State in the world by both area and population, but formally it is not sovereign, sovereignty being held by the Holy See, the only entity of public international law that has diplomatic relations with almost every country in the world., Bolzano (or ; German: "Bozen", ; Ladin: "Balsan" or "Bulsan") is the capital city of the province of South Tyrol in northern Italy. With a population of 105,713 (2013), Bolzano is also by far the largest city in South Tyrol.
Bolzano is the seat of the Free University of Bozen-Bolzano, where lectures and seminars are held in English, German and Italian. The city is also home to the Italian Army's Alpini High Command (COMALP) and some of its combat and support units., The Pragser Bach ( Italian : Rio Braies ) is a stream in South Tyrol , Italy ., Italy, officially the Italian Republic, is a unitary parliamentary republic in Europe. Located in the heart of the Mediterranean Sea, Italy shares open land borders with France, Switzerland, Austria, Slovenia, San Marino and Vatican City. Italy covers an area of and has a largely temperate seasonal climate and Mediterranean climate; due to its shape, it is often referred to in Italy as "lo Stivale" (the Boot). With 61 million inhabitants, it is the fourth most populous EU member state., Subject: pragser bach, Relation: instance_of, Options: (A) 12 (B) army (C) autonomous province (D) body of water (E) border (F) capital (G) census (H) channel (I) city (J) climate (K) code (L) communication (M) confederation (N) country (O) data (P) dialect (Q) fashion (R) footwear (S) government (T) head of state (U) hungary (V) italy (W) law (X) legislature (Y) may (Z) mediterranean sea ([) member (\) name (]) nation (^) norm (_) number (`) ocean (a) official (b) parliament (c) part (d) peninsula (e) plateau (f) region (g) republic (h) river (i) romance (j) seat (k) shape (l) sign (m) size (n) spa (o) standard (p) steel (q) style (r) system of government (s) territory (t) the city (u) three (v) town (w) two (x) union (y) valley (z) variety ({) water
Output:
river