The correct answer is A. Patna.
The East Central Railway zone is one of the 18 railway zones of Indian Railways. It is headquartered at Patna, Bihar. The zone was formed on 1 April 1996 by bifurcating the Eastern Railway zone. It covers the states of Bihar, Jharkhand, Odisha, and West Bengal. The zone has a total route length of 4,950 km and a total track length of 10,200 km. It has 10 divisions, 12 workshops, and 11 training institutes. The zone operates a fleet of over 3,000 locomotives and over 10,000 coaches. It carries over 1.5 billion passengers and over 100 million tonnes of freight annually.
The East Central Railway zone is one of the busiest railway zones in India. It plays a vital role in the economic development of the region. The zone provides a vital link between the major cities of the region and the rest of the country. It also plays a major role in the transportation of coal, iron ore, and other minerals from the region.
The East Central Railway zone is a well-managed and efficient railway zone. It has a strong track record of safety and performance. The zone is committed to providing quality services to its customers.