How did European diseases affect the Americas? A. European diseases killed many buffalo and deer.
B. European diseases infected American crops.
C. European diseases killed many people.
D. European diseases infected the water in desert areas.

C. European diseases killed many people.

Explanation:

The Natives were not immune to diseases that the outsiders brought in to their country, which led to them dying in large amount of numbers.

what are local authorities doing to fix the problem

explanation:

the noble might have thought that the system was far because they had lot of things and riches and the serf would have thought that the feudal system was un fair because of the way they were treated.