The correct answer is B.
Fidel Castro leaded the Cuban Revolution, an armed offensive that intended to expel the dictator Fulgencio Batista from the Cuban goverment, claiming that he was serving the economic interests of other countries, such as the US, rather than the interests of his citizens.
The expedition leaded by Castro arrived from exile in Mexico to Cuba in 1953 and the revolution started. Many years of guerrilla warfare around Sierra Maestra and of gathering the support of the majority of the Cuban population took place until the revolutionary expedition could achieve major advances, until it finally succeeded in 1959.