Which factor did not play a part in the spanish conquest of the aztec and inca empire

"African slaves outnumbered the indigenous population by nearly 50 percent" was the one factor among the following choices given in the question that did not play a part in the Spanish conquest of the Inca and Aztec empires.

.

Explanation:

it was a act of seld fesnse more over it was a peace treaty between the fogein contunries.

i think it's a)sparta