Which two events weakened the inca empire prior to the spanish conquest?
civil war and diseases
drought and famine
decline in trade and an uprising among neghboring people
a devastating earthquake and tidal wave

civil war and diseases

Explanation:

The Inca empire compreended a large part of west South America during the 14th and the 15th century, until it was conquered by spain. The "capital" of the empire was the city of Cusco, in Peru.

In the 15th century, there was the Inca Civil War between two brothers for the throne of the empire, and diseases such as influenza and typhus had spread across South America. With this, the power of the empire weakened and it was conquered by Spain in 1572.

So the correct answer is:

civil war and diseases

the answers is b.   environments.

the doctrine of nullification recommended that states living inside the union have the one-sided, inalienable ideal to void any law made by the national government that could be esteemed illegal.

the united states was shaped based on a general agreement among its individual states. hence, it is inferred that under the hypothesis of invalidation, since the states are the establishment of the union, they have the ability to referee and disprove unlawful laws.