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: Sussex (abbreviated Sx), from the Old English "Sþsaxe" (South Saxons), is a historic county in South East England corresponding roughly in area to the ancient Kingdom of Sussex. It is bounded to the west by Hampshire, north by Surrey, north-east by Kent, south by the English Channel, and divided for local government into West Sussex and East Sussex and the city of Brighton and Hove. Brighton and Hove was created as a unitary authority in 1997, and granted City status in 2000. Until then, Chichester was Sussex's only city., Maidstone is the county town of Kent, England, south-east of London. The River Medway runs through the centre of the town, linking it with Rochester and the Thames Estuary. Historically, the river was a source and route for much of the town's trade as the centre of the agricultural county of Kent, known as the Garden of England. There is evidence of a settlement in the area dating back to before the Stone Age., A County town is usually the location of administrative or judicial functions within the county, or it has been established over time as the "de facto" main town of a county. The concept of a county town eventually became detached from its original meaning of where the county administration or county hall is based. In fact, many county towns are no longer part of the administrative county. For example, Nottingham is administered by a unitary authority entirely separate from the rest of Nottinghamshire. Many county towns are classified as cities, but all are referred to as county towns regardless of whether city status is held or not., Chalk is chiefly a suburb but also a civil parish which adjoins the east of Gravesend , Kent , England . As is intuitive , its name comes from the Saxon word cealc meaning a chalkstone . One layer of the chalk carries flints , stones embedded in the chalk , and these were used in building and in providing the means of fire for muskets . The stone is often cut to provide a flat edge as a craft known as flint - knapping . The trade was worked in Chalk from the 17th century onwards . Gun - flints were produced here in large quantities until the early 19th century . Current issues relating to the immediate environment around Chalk include a proposed new Lower Thames Crossing through Shorne Wood Country Park and across the estuary marshes at Chalk , being reconsidered in 2013 , and a new Thames Estuary Airport resulting in low flying aircraft over the village from the Isle of Grain ., The Thames Estuary is the estuary in which the River Thames meets the waters of the North Sea, in the south-east of Great Britain., East Sussex is a county in South East England. It is bordered by the counties of Kent to the north and east, Surrey to the north west and West Sussex to the west, and to the south by the English Channel., Kent is a county in South East England and one of the home counties. It borders Greater London to the north west, Surrey to the west, East Sussex to the south west, and Essex across the Thames Estuary to the north. The county town is Maidstone. , Subject: chalk, Relation: located_next_to_body_of_water, Options: (A) english channel (B) main (C) north sea (D) river medway (E) river thames
Output:
river thames