The correct answer is B. 1895.
Hockey was introduced to Patna College in 1895 by a British professor named Edward Thornton. He was a keen hockey player and he started a hockey team at the college. The team was very successful and they won many matches. This led to the popularity of hockey in Patna and other parts of Bihar.
Option A is incorrect because hockey was not introduced to Patna College in 1844. The college was founded in 1847.
Option C is incorrect because hockey was not introduced to Patna College in 1904. The college team won the All India Hockey Championship in 1904, but this does not mean that hockey was introduced to the college in that year.
Option D is incorrect because hockey was introduced to Patna College in 1895, not 1966.