Whih of the following was the most important factor in enabling the Spanish to defeat the Aztec Empire ?

A. The Spanish were able to field larger armies than in the Aztecs.
B. Spanish tolerance of Aztec religion and culture weakened Aztec resistance.
C. The Spanidh were able to exploit the poverty in the Aztec Empire which caused a revolt of Aztec farmers against the Aztec ruling class
D. The Spanish were able to form military alliances with other indigenous people's who were enemies of the Aztecs.

2 answers

The answer is in your book. You will also find the answer immediately if you search the internet for Spanish colonization of Mexico. Coming here to avoid reading the chapter in the text is not good.
D. The Spaniards had important alliances with other indigenous peoples who were enemies of the Aztecs. The most notable of these alliances was with the Tlaxcalans.