The most accurate response regarding the role of horses in the conquest of the Aztec and the Inca is:
Spaniards used horses to intimidate their opponents and demonstrate superiority and dominance in battle.
Horses provided the Spanish conquistadors with a significant tactical advantage due to their speed, mobility, and the psychological impact they had on the indigenous forces, who were not accustomed to mounted combat. This could lead to demoralization and confusion among the Aztec and Inca warriors during battles.