The correct option is C Construction of Railways
Indeed construction of railways is the biggest contribution to India by the Britishers. Today railway is known as the "life line "of our country . Indian Railways, which had a modest beginning in 1853, has since then been an integral part of the nation. A network that has held together a population of one billion. A self-propelled social welfare system the Indian Railways has woven a sub-continent together and brought to life the concept of a united India.