Why were sports becoming more popular both at the high school and college level and at the professional level?

because adults didn't trust boys to play unsupervised, attention soon shifted to organized sports. Sports were seen as important in teaching the “American” values of cooperation, hard work, and respect for authority.

Explanation:

for the united states of america, 1945 to 1964 was a time of high economic growth and general prosperity. it was also a time of confrontation as the capitalist united states and its allies politically opposed the soviet union and other communist countries; the cold war had begun.

explanation:

c or d both can be the answer