The correct answer is: a) Lord Dalhousie.
Lord Dalhousie was the Governor-General of India from 1848 to 1856. He is best known for his policy of annexation, which led to the conquest of Punjab in 1849. He also played a key role in the administration of Punjab, and his reforms helped to modernize the region.
Lord Curzon was the Viceroy of India from 1899 to 1905. He is best known for his reforms of the Indian education system, and for his construction of the Delhi Durbar. He did not play a key role in the conquest or administration of Punjab.
Lord Wellesley was the Governor-General of India from 1798 to 1805. He is best known for his wars against the Maratha Empire, and for his expansion of British power in India. He did not play a key role in the conquest or administration of Punjab.
Lord Canning was the Governor-General of India from 1856 to 1862. He is best known for his role in the Indian Rebellion of 1857. He did not play a key role in the conquest or administration of Punjab.