When did lord Dalhousie become the Governor General of India?
The correct option is B 1848 A.D.
Lord Dalhousie served as Governor General of India from 1848 to 1856. During this period Dalhousie was successful in annexing Punjab to the British administration. He annexed many states by 'Doctrine of Lapse'. During his governorship first railway line between Mumbai to Thane was opened in 1853 and in the same year Calcutta and Agra were connected by Telegraph.