In which year did Lord Dalhousie introduce the railway line in British India?

The correct option is 1853.

Explanation:
The railway system in British India was introduced during the tenure of Lord Dalhousie, who served as the Governor-General of India from 1848 to 1856.
On April 16, 1853, the first passenger train in India ran between Bori Bunder (Bombay) and Thane, covering a distance of approximately 34 kilometers (21 miles). The train was operated by the Great Indian Peninsula Railway (GIPR) and pulled by three steam engines named Sahib, Sindh, and Sultan.

Due to his pivotal role in developing modern infrastructure in India—including railways, electric telegraph, and modern postal services—Lord Dalhousie is commonly referred to as the "Father of Indian Railways".