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: Surrey is a county in the south east of England and also one of the home counties bordering Greater London. Surrey shares borders with Kent to the east, East Sussex to the south-east, West Sussex to the south, Hampshire to the west and south-west and Berkshire to the north-west. The county town is Guildford. Surrey County Council sits extraterritorially at Kingston upon Thames, administered as part of Greater London since 1965. With a resident population of 1.1 million, Surrey is the most densely populated and third most populated county in the South East region, after Kent and Hampshire., The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a sovereign country in western Europe. Lying off the north-western coast of the European mainland, it includes the island of Great Britain (the name of which is also loosely applied to the whole country), the north-eastern part of the island of Ireland, and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another sovereign statethe Republic of Ireland. Apart from this land border, the UK is surrounded by the Atlantic Ocean, with the North Sea to its east, the English Channel to its south and the Celtic Sea to its south-south-west, giving it the 12th-longest coastline in the world. The Irish Sea lies between Great Britain and Ireland. With an area of , the UK is the 78th-largest sovereign state in the world and the 11th-largest in Europe. It is also the 21st-most populous country, with an estimated 65.1 million inhabitants. Together, this makes it the fourth most densely populated country in the European Union., Gloucestershire (; abbreviated Glos.) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn, and the entire Forest of Dean., Wiltshire (or ) is a county in South West England with an area of . It is landlocked and borders the counties of Dorset, Somerset, Hampshire, Gloucestershire, Oxfordshire and Berkshire. The county town was Wilton but Wiltshire Council is now based in the new county town of Trowbridge., Thames Water Utilities Ltd, known as Thames Water, is the private utility company responsible for the public water supply and waste water treatment in large parts of Greater London, the Thames Valley, Surrey, Gloucestershire, Wiltshire, Kent, and some other areas of the United Kingdom. Thames Water is the UK's largest water and wastewater services company, and supplies of drinking water per day, and treats of wastewater per day. Thames Water's 15 million customers comprise 27% of the UK population., The Thames Valley region is a loose term for the English counties or parts of those counties roughly following the course of the River Thames as it flows from Oxfordshire in the west to London in the east. It is generally taken to include parts of Oxfordshire, Buckinghamshire, Berkshire, Surrey and sometimes two boroughs of southwest London. It rarely includes either the source of the Thames at Thames Head in Gloucestershire, or any part of Wiltshire, and does not include the informal entities Central London or the Thames Gateway which surrounds the Thames Estuary., The Thames Water Authority was one of ten regional water authorities created in the UK in 1975 to bring together all the water management functions of the region in one public body . The bodies subsumed included the Metropolitan Water Board , the Thames Conservancy , the Lee Conservancy Catchment Board and parts of the Essex River Authority and the Kent River Authority which had formerly regulated the north bank and the south bank of the River Thames estuary . In 1989 the Thames Water Authority was partly privatised , with the water and sewage responsibilities transferring to the newly established publicly quoted company of Thames Water , and the regulatory responsibilities transferring to the newly created National Rivers Authority, 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: thames water authority, Relation: headquarters_location, Options: (A) central (B) central london (C) east sussex (D) england (E) essex (F) europe (G) forest (H) gloucestershire (I) guildford (J) ireland (K) kent (L) kingston (M) kingston upon thames (N) london (O) maidstone (P) oxfordshire (Q) somerset (R) south east england (S) surrey (T) united kingdom (U) wiltshire
Output:
london