Final answer:
The Native Americans did not have better weapons than the Spanish, which is the factor that did not contribute to Spain's victory. Superior Spanish military technology and alliances, as well as the devastating impact of European diseases on Native Americans, were key to the Spanish conquest.
Step-by-step explanation:
The factor that did NOT play a role in Spain winning against the Native Americans was B: The Native Americans had better weapons. In fact, the Spanish conquest was facilitated by a combination of factors, including the Spanish having superior weaponry and armor, and strategic alliances with local tribes who opposed the Aztecs. The Native Americans suffered greatly from European diseases such as smallpox, to which they had no immunity, significantly weakening their societies. The contagious diseases brought by Europeans spread quickly among the Native American population, causing large numbers of deaths.