Most Cubans who came to the U.S. in the 1960s and 1970s were seeking what?A) business opportunities // B) escape from Fidel Castro's Communist...

The best answer of the ones that you offer us is B.  In
general, Cubans escapeing from Cuba and coming to the United States in these decades
came because they wanted to get away from the communist regime led by Fidel
Castro.

The Castro regime had come to power in the late
1950s in Cuba.  Castro soon imposed a very strict set of rules on Cuba, basing them on
ideas of communism.  These stifled human rights such as free speech.  The rules also
destroyed private enterprise in Cuba.  Because many Cubans thought that they would be
better off both economically and in terms of rights in the US, they tried to leave Cuba
and come to the US.

Therefore, B is the best of these
answers.