National Sports Day is celebrated on 29th August, which is related to –

Dhyan Chand
Milkha Singh
Daleep Singh
C.K. Nayadu

National Sports Day is celebrated on 29 August every year in India to commemorate the birth anniversary of Major Dhyan Chand, who is considered to be the “Father of Indian Hockey”. He was a field hockey player who represented India from 1926 to 1948 and is widely regarded as one of the greatest field hockey players of all time. He led the Indian team to three Olympic gold medals (1928, 1932, and 1936) and scored over 1,000 goals in his career.

Milkha Singh was an Indian track and field sprinter who was nicknamed “The Flying Sikh”. He is the only Indian athlete to have won an individual athletics gold medal at the Commonwealth Games (1958) and the Asian Games (1958). He also competed at the 1960 Summer Olympics, where he finished fourth in the 400 metres final.

Daleep Singh was an Indian field hockey player who represented India from 1956 to 1966. He was a member of the Indian team that won the gold medal at the 1964 Summer Olympics. He was also a member of the Indian team that won the gold medal at the 1962 Asian Games.

C.K. Nayadu was an Indian cricketer who played for India from 1946 to 1959. He was a right-handed batsman and a right-arm off break bowler. He was the first Indian cricketer to score a century in Test cricket against England. He was also the first Indian cricketer to take a hat-trick in Test cricket.

Therefore, the correct answer is A.