You will be given a definition of a task first, then some input of the task.
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).

Context: Adelaide is the capital city of the state of South Australia, and the fifth-most populous city of Australia. In June 2014, Adelaide had an estimated resident population of 1.31 million. South Australia, with a total of 1.7 million inhabitants, has the most centralised population of any state in Australia, with more than 75 percent of its people living in greater Adelaide, while the other population centres in the state are relatively small., South Australia (abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories. It has a total of 1.7 million people, and its population is the most highly centralised of any state in Australia, with more than 75 percent of South Australians living in the capital, Adelaide, or its environs. Other population centres in the state are relatively small., Mount Bold Reservoir is the largest reservoir in South Australia with a maximum capacity of over forty-six thousand megalitres. Costing A$1.1 million, the reservoir took six years to construct on the Onkaparinga River system between 1932 and 1938. The reservoir does not connect directly to the main reticulation system; rather, to maintain levels at Clarendon Weir, water is released only as required. Much of the water from Mount Bold will eventually end up at Happy Valley Reservoir and used to supply parts of the Mount Lofty Ranges and also Adelaide., A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features, although in some countries or communities a stream is defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague., A weir is a barrier across a river designed to alter the flow characteristics. In most cases weirs take the form of a horizontal barrier across the width of a river that pools water behind it whilst still allowing it to flow steadily over the top. Weirs are commonly used to prevent flooding, measure discharge and help render rivers navigable. In some places the crest of an overflow spillway on a large dam may also be called a weir., The Clarendon Weir is a small weir on the Onkaparinga River , near Adelaide in South Australia . Built in 1894 -- 96 as part of the early Onkaparinga Water Scheme , the weir was designed to pool water from the Mount Bold Reservoir , on the Onkaparinga , which is often boosted with water from the River Murray . From the weir water is directed onwards to Happy Valley Reservoir in the Field River catchment through pipeline . The water is used to supply the majority of the Adelaide region 's water needs . The Clarendon Weir wall , originally constructed with large blocks of Macclesfield marble , was raised to its current height of 14.5 metres ( 48 ft ) in the mid- 1960s ., Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It is the world's sixth-largest country by total area. The neighbouring countries are Papua New Guinea, Indonesia and East Timor to the north; the Solomon Islands and Vanuatu to the north-east; and New Zealand to the south-east. Australia's capital is Canberra, and its largest urban area is Sydney., An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea., The Onkaparinga River is a river located in South Australia south of the Adelaide city centre. It runs from its source between Mount Torrens and Charleston in the Mount Lofty Ranges, and flows south westerly to an estuary at Port Noarlunga., The Mount Lofty Ranges are the range of mountains just to the east of Adelaide in South Australia., The kangaroo is a marsupial from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, especially those of the genus "Macropus": the red kangaroo, antilopine kangaroo, eastern grey kangaroo, and western grey kangaroo. Kangaroos are endemic to Australia. The Australian government estimates that 34.3 million kangaroos lived within the commercial harvest areas of Australia in 2011, up from 25.1 million one year earlier., A dam is a barrier that impounds water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions., Adelaide city centre is the innermost locality of Greater Adelaide, the capital city of South Australia. It is known by locals simply as ""The City"" or ""Town"" to distinguish it from Greater Adelaide and from the City of Adelaide (which also includes North Adelaide and the parklands). The locality is split into two key geographical distinctions: the city "square mile", bordered by North, East, South and West Terraces; and the section of the Adelaide Parklands south of the River Torrens which separates the built up part of the city from the surrounding suburbs and North Adelaide. , The Happy Valley Reservoir is a water reservoir located in Adelaide, Australia. Constructed when the total population of Adelaide numbered 315,200 (1893 census), the Happy Valley Reservoir now supplies over a half a million people, from Adelaide's southern extent to the city-centre. It is also home to lots of wildlife including many kangaroos., Subject: clarendon weir, Relation: instance_of, Options: (A) 1 (B) 25 (C) body of water (D) brackish water (E) capital (F) city (G) country (H) course (I) dam (J) england (K) estuary (L) family (M) genus (N) geographic location (O) geographical (P) government (Q) home (R) june (S) lake (T) location (U) may (V) ocean (W) people (X) population (Y) range (Z) reservoir ([) river (\) sea (]) six (^) state (_) stream (`) term (a) town (b) valley (c) water (d) water reservoir (e) watercourse (f) weir (g) year
Output:
dam