The correct answer is d. it was a failure that was an embarrassment for the Kennedy administration. It was not only a complete military fiasco, it was a political debacle as the USA appeared to the world as aggressors and prompted the Soviets to increase their military aid to Cuba which would ultimately turn into the Cuban Missile Crisis barely a year later. The attempted invasion unified and solidified Cuban communists and radicalized Castro against the USA. Public opinion in most of Central and South America was that Americans were hypocrites who would parrot words as democracy, sovereignty and peaceful cooperation and then spearhead an invasion of reactionary, right-wing elements to a smaller Caribbean nation.
Untouchables were the people in society who were deemed as less than human. They were the people that cleaned up the streets, took care of dead bodies... They had to do what no one else in society wanted to do pretty much.
Khmer Rouge was the name popularity given to the followers of the Communist party of Kampuchea. Which the CPK ruled in Cambodia between the 1975 and 1979.