How did the Columbian Exchange make the Spanish conquest of the New World easier?

The Columbian Exchange greatly increased the food supply in the Old World. The Columbian Exchange made the Spanish Conquest of the New World easier because of diseases. Diseases such as smallpox weakened the Aztecs and the Incas when the Spanish tried to take them over, it was easier.

To be honest i thinks its between the first answer and the third answer

Ithink it is something and something