Answer:
The answer is A.
Step-by-step explanation:
Grasshoppers are a food of mice. If the mice went extinct, then there will be a population boom of grasshoppers. At the same time, the number of plants will decrease because of this. Also, the snake will not be able to survive because of the lack of mice (other species can survive to this change, though).
(I hope this helps! I learned this a long time ago, so yeah!)