What is the cause of the majority of overgrazing? 

A)  too many animals permitted to stay in one place for too long 
B)  increased temperatures due to climate change 
C)  large populations of wild herbivores 
D)  increased drought due to climate change

Overgrazing

The depletion of vegetation due to continuous feeding by an excessive number of grazing animals, leading to soil erosion and decreased agricultural productivity.

Climate Change

The long-term alteration of temperature and typical weather patterns in a place, largely attributed to human activities such as fossil fuel burning which releases greenhouse gases.