Given the question: Information:  - The British Railways Board (BRB) was a nationalised industry in the United Kingdom that operated from 1963 to 2001. Until 1997 it was responsible for most railway services in Great Britain, trading under the brand name British Railways and, from 1965, British Rail. It did not operate railways in Northern Ireland, where railways were the responsibility of the Government of Northern Ireland.  - Sheffield is a city and metropolitan borough in South Yorkshire, England. Historically part of the West Riding of Yorkshire, its name derives from the River Sheaf, which runs through the city. With some of its southern suburbs annexed from Derbyshire, the city has grown from its largely industrial roots to encompass a wider economic base. The population of the City of Sheffield is and it is one of the eight largest regional English cities that make up the Core Cities Group. Sheffield is the third largest English district by population. The metropolitan population of Sheffield is 1,569,000.  - Cravens Railway Carriage and Wagon Company Limited was a railway rolling stock builder in the Darnall district of Sheffield, England. Founded by brothers named Craven and known as Craven Brothers, later Cravens Limited, it remained a family business until John Brown & Company acquired a controlling shareholding in 1919. Its name was changed back to Cravens Limited in 1954 when it finally became a wholly owned subsidiary of John Brown.  Ownership. Two Sheffield-raised Craven brothers, sons of a Wakefield mason and builders themselves began to make railway wagons in 1866 when railway companies also pulled wagons, particularly purpose-built wagons, for other owners. A third brother, previously an architect and timber merchant, soon joined them.  - British Railways (BR), which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages between 1994 and 1997. Originally a trading brand of the Railway Executive of the British Transport Commission, it became an independent statutory corporation in 1962: the British Railways Board.   - The British Transport Commission (BTC) was created by Clement Attlee's post-war Labour government as a part of its nationalisation programme, to oversee railways, canals and road freight transport in Great Britain (Northern Ireland had the separate Ulster Transport Authority). Its general duty under the Transport Act 1947 was to provide "an efficient, adequate, economical and properly integrated system of public inland transport and port facilities within Great Britain for passengers and goods", excluding transport by air.  - The Core Cities Group (also Core Cities UK) is a self-selected and self-financed collaborative advocacy group of large regional cities in the United Kingdom and outside Greater London. The group was formed in 1995 as a partnership of eight city councils: Birmingham, Bristol, Leeds, Liverpool, Manchester, Newcastle, Nottingham, and Sheffield. The Core Cities Group has wide ranging interests, encompassing transport and connectivity, innovation and business support, skills and employment, sustainable communities, culture and creative industries, climate change, finance and industry, and governance. During 2012 the first wave of 'city deals' recognised the eight cities as "the largest and most economically important English cities outside of (sic) London".  - South Yorkshire is a metropolitan county in England. It is the southernmost county in the Yorkshire and the Humber region and had a population of 1.34 million in 2011. It has an area of and consists of four metropolitan boroughs, Barnsley, Doncaster, Rotherham and Sheffield. South Yorkshire was created on 1 April 1974 as a result of the Local Government Act 1972 with Barnsley as its county town.  - England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west. The Irish Sea lies northwest of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain (which lies in the North Atlantic) in its centre and south; and includes over 100 smaller islands such as the Isles of Scilly, and the Isle of Wight.  - The British Rail Class 105 diesel multiple units were built by Cravens Ltd. of Sheffield from 1956 to 1959 . The class were built with a side profile identical to British Railways Mark 1 carriage stock , using the same doors and windows . None were selected for refurbishment . The last passenger car was withdrawn from service in 1988 .    After reading the paragraphs above, we are interested in knowing the entity with which 'british rail class 105' exhibits the relationship of 'manufacturer'. Find the answer from the choices below.  Choices: - bristol  - cravens railway carriage and wagon company limited  - humber  - northern ireland  - united kingdom
The answer is:
cravens railway carriage and wagon company limited