CORRECT answer is Rajdhani Express.The Kolkata-New Delhi Rajdhani Express embarked on its maiden journey on 3 March 1969 from Howrah, making it the COUNTRY's first FULLY air-conditioned, high-speed train.It covered the 1,450-kilometre stretch in 17 hours and 20 minutes.Facts about Indian Railways:Father of Indian Railways: DalhousieThe railway runs more than 7,421 cargo trains carrying 3 million tons of freight daily.Indian Railways is the world’s second-largest network operated under a single ADMINISTRATION and the largest rail network in Asia.Indian Railways started computerized reservations in New Delhi in 1986.Toilets were introduced on Indian Railways in 1909.Indian Railways was nationalized in 1951They are Darjeeling-Himalayan Railway, Nilgiri Mountain, Mumbai CST, and Kalka-Shimla Railways.Four sites of Indian Railways have been declared as “World Heritage sites” by UNESCO.The Fairy Queen is the oldest functioning steam engine in the world. It is plying between New Delhi and Alwar in RAJASTHAN.