The defeat of the Aztec and Incan empires significantly enriched the Spanish monarchy primarily through the vast riches that were obtained from these conquests. This included enormous amounts of gold, silver, and other valuable resources taken from the territories. The Spanish monarchy profited from this wealth as the conquistadors often sent a portion of their plunder back to the crown. Additionally, the establishment of colonies in the Americas allowed Spain to levy taxes on the colonists and exploit the local resources further enriching the monarchy.
Thus, the correct response would be:
The monarchy received a portion of all treasures taken by the conquistadors.