Which communist leader did the United States try to overthrow in Cuba during the early 1960s?

Ithink the answer is b

One of the things that allowed native americans in mexico to settle cities larger than those in areas to the north was "b. the development of cities that were built by an earlier civilizations," since mexico had been the home of some of the world's most advanced civilizations before the columbian invasion

The answer is a. : ) ; )