The correct answer to this open question is the following.
Although there are no options attached we can say the following.
America's attempt at overthrowing Castro during the Bay of Pigs failed because the federal government of the United States failed to correctly prepare the invasion and did not support the military operation as it was supposed to support a serious plan like this. Some historians considered that the US government underestimated Fidel Castro's military skills. There are even some versions that say that Fidel Castro knew about the US plans to invade Cuba so he could prevent his troops and were ready to fight the US soldiers.
After Communist leader Fidel Castro had overthrown Fulgencio Batista as the President of the Island of Cuba, the White House supported an invasion to defeat Castro's troops and reinstall a democratic capitalist form of government. The operation started on April 17, 1961, and was led by Cuban exiles with the support of US troops. However, it failed right away. The Soldiers of Castro defeated the invaders and in just one day the operation had ended.
This led to the international incident known as the Cuban Missile Crisis of October 1962 in which the world was on the brink of another world war due to the presence of USSR missiles on the island of Cuba aiming at the United States territory.