B. the strategy and tactics of the Spaniard military.
Explanation:
The Native American forces were largely depleted by the time Spaniards attacked them due to the large scale famines.
However, the forces were still pretty huge and could have defeated the Spaniards.
the Spaniards had more tactical acumen and had defectors from the other side who told them about the Native war strategies in detail.
They had enough time to formulate their own war strategies against them.
They also had a technological advantage over the Inca with the gunpowder which made things favorable for them.
