The execution of the last Inca ruler, Atahualpa was the act of the conquistador Pizarro, crucial in overthrowing the Inca. Option C is correct.
Francisco Pizarro González was a Spanish conquistador who led the Spanish conquest of the Inca Empire. He kidnapped and killed Incan emperor Atahualpa, and claimed the lands for Spain. On 10 November 1509, Pizarro sailed from Spain to the New World along with Alonso de Ojeda on an expedition to Gulf of Urabá in Tierra Firme.
The reaction of the people of America on the overseas expansion was that they supported this overseas expansion in the period of 1800s.
They supported it because they wanted to increase trade in the regions of Latin America, to spread the idea of democracy and try to influence other countries so that it could bring as many countries under it's control.
It also wanted this over seas expansion to expand America over other countries. All this led to the growth of income, wealth of the people of America.