Why were Cortes and Pizarro able to defeat the Aztecs and the Incas?
a. The European weapons proved vastly superior against the defenseless Indians who had previously existed peacefully with their neighbors and therefore did not need weapons
b. The European conquistadores greatly outnumbered both the small empires of the Aztecs and the Incas
c. The Europeans used the element of surprise to startle and disorient both Indian groups who were afraid of the white Europeans.
d. The Europeans carried deadly diseases which decimated the populations of both the Aztecs and the Incas and thus undermined their political and military order