The correct answer is: A. 15th Jan, 1958
The North Eastern Frontier Railway (NEFR) is one of the 18 railway zones of Indian Railways. It is headquartered in Maligaon, Guwahati, Assam. The NEFR was established on 15 January 1958 by merging the Assam Railway and Avadh-Tirhut Railway. The NEFR is responsible for operating and maintaining railway lines in the northeastern states of India. It has a total route length of 3,327 km, of which 2,895 km is broad gauge and 432 km is meter gauge. The NEFR has a total of 1,084 stations, of which 23 are major stations. The NEFR operates a fleet of over 1,500 locomotives and over 10,000 coaches. The NEFR is a vital link for the northeastern states of India. It provides transportation for passengers and goods, and it also plays a role in the economic development of the region.
Option B is incorrect because the North Eastern Frontier Railway was established on 15 January 1958, not 15 January 1955.
Option C is incorrect because the North Eastern Frontier Railway was established on 15 January 1958, not 2 January 1956.
Option D is incorrect because the North Eastern Frontier Railway was established on 15 January 1958, not 14 April 1952.