Given the question: Information:  - The Karelian Isthmus is the approximately 45110 km wide stretch of land, situated between the Gulf of Finland and Lake Ladoga in northwestern Russia, to the north of the River Neva (between 61°21N, 59°46N and 27°42E, 31°08E). Its northwestern boundary is the relatively narrow area between the Bay of Vyborg and Lake Ladoga. If the Karelian Isthmus is defined as the entire territory of present-day Saint Petersburg and Leningrad Oblast to the north of the Neva, the isthmus' area covers about 15,000 km.  - Kurort, is a railway station in Sestroretsk, Russia.  - Beloostrov (both meaning lit. "White Island"), from 1922 to World War IIKrasnoostrov (lit. "Red Island"), is a municipal settlement in Kurortny District of the federal city of St. Petersburg, Russia, located on the Sestra River, Karelian Isthmus. Population:   - Primorskaya railway was located near Saint Peterburg and it lay on the route Saint Peterburg , Sestroretsk , Beloostrov . The railway was served by steam locomotives from the moment of opening and before joining to Oktyabrskaya railway in 1925 .  - Finland , officially the Republic of Finland, is a sovereign state in Northern Europe. A peninsula with the Gulf of Finland to the south and the Gulf of Bothnia to the west, the country has land borders with Sweden to the northwest, Norway to the north, and Russia to the east. Estonia is south of the country across the Gulf of Finland. Finland is a Nordic country situated in the geographical region of Fennoscandia, which also includes Scandinavia. Finland's population is 5.5 million (2014), staying roughly on the same level over the past two decades. The majority of the population is concentrated in the southern region. In terms of area, it is the eighth largest country in Europe and the most sparsely populated country in the European Union.  - The Gulf of Finland  is the easternmost arm of the Baltic Sea. It extends between Finland (to the north) and Estonia (to the south) all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn. The eastern parts of the Gulf of Finland belong to Russia, and some of Russia's most important oil harbours are located farthest in, near Saint Petersburg (including Primorsk). As the seaway to Saint Petersburg, the Gulf of Finland has been and continues to be of considerable strategic importance to Russia. Some of the environmental problems affecting the Baltic Sea are at their most pronounced in the shallow gulf.  - Russia (from the  Rus'), also officially known as the Russian Federation, is a country in Eurasia. At , Russia is the largest country in the world by surface area, covering more than one-eighth of the Earth's inhabited land area, and the ninth most populous, with over 140 million people at the end of March 2016. The European western part of the country is much more populated and urbanised than the eastern, about 77% of the population live in European Russia. Russia's capital Moscow is one of the largest cities in the world, other major urban centers include Saint Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod and Samara.  - Kurortny District is a district of the federal city of St. Petersburg, Russia, located on the Karelian Isthmus along the northern shore of the Gulf of Finland. As of the 2010 Census, its population: was 70,589; up from 67,511 recorded in the 2002 Census.  - Sestroretsk  is a municipal town in Kurortny District of the federal city of St. Petersburg, Russia, located on the shores of the Gulf of Finland, the Sestra River and the Sestroretskiy Lake northwest of St. Petersburg. Population: 30,500 (1975).    After reading the paragraphs above, we are interested in knowing the entity with which 'primorskaya railway' exhibits the relationship of 'instance of'. Find the answer from the choices below.  Choices: - area  - census  - city  - district  - federation  - geographical  - gulf  - island  - isthmus  - lake  - march  - oblast  - peninsula  - people  - population  - railway station  - region  - republic  - river  - saint  - sea  - surface  - town  - union  - war  - world war
The answer is:
railway station