They did not allow the native americans to stay, they were basically evicted.
The Spanish conquistadors believed them to be infidels. They would read them a note from the Pope in Spanish that they wouldn't understand in which they would proclaim that their land would now be Spanish because Spain is governed by one true God, and after that they would slaughter them if they wouldn't surrender.
C to overthrow the government and establish a new one.
Based on information, your corrct answer would be Option C. Before battles, the Persian Empire became very strong, and they had a good leadership mainly because of Cyrus. And because they were so strong and they had enough power, they simply just drove them out of their land and expanded there land control over to Asia.