The most accurate answer regarding the result of the Cuban Revolution (which culminated in 1959) is:
A) the U.S. trade embargo on Cuba.
The Cuban Revolution led to the establishment of a communist government under Fidel Castro, which caused significant tensions between Cuba and the United States. As a result, the U.S. imposed a trade embargo on Cuba in 1960, which remains in effect to varying degrees.
The other options do not correctly reflect the direct results of the Cuban Revolution:
B) The U.S. did not begin trading and profiting from the Cuban economy; rather, the embargo restricted U.S. trade with Cuba.
C) Cuba's independence from Spain occurred in 1898, long before the Cuban Revolution.
D) While there were economic changes post-revolution, claiming a population increase due to economic prosperity is misleading, as the overall economic conditions became quite difficult due to the embargo and other factors.