The correct answer is: A. 1955
Milkha Singh won his first National title in the 400 m race in 1955. He was born in 1929 in Punjab, British India. He started running at the age of 14 to escape the violence of the Partition of India. He won his first major international medal at the 1958 Asian Games, where he won the gold medal in the 400 m race. He went on to represent India at the 1960 Summer Olympics, where he finished fourth in the 400 m final. He is considered to be one of the greatest Indian athletes of all time.
Option B is incorrect because Milkha Singh won his first National title in the 400 m race in 1955, not 1956.
Option C is incorrect because Milkha Singh won his first National title in the 400 m race in 1955, not 1957.
Option D is incorrect because Milkha Singh won his first National title in the 400 m race in 1955, not 1970.