How did the spanish conquistador francisco pizarro conquer the incans by 1535? select one: a. the incans were frightened by the spaniards and did not resist his forces. b. the spanish forced atahualpa, the last inca emperor, to surrender to the spanish. c. the incans were already weakened militarily and divided because of rival claimants to the throne. d. he had a large force of 1,000 men and 500 horses and easily overwhelmed the incans?