What might cause the population of trees and grasses increase in this food web?

The population of all plants will decrease.

Explanation:

As you can see, if the hunting of grey wolves becomes unrestricted the population of grey wolves would decreased, this means that the natural predator for Elks and mule deer will be diminished, which means that not enough Elks and mule deers will be eaten, this would increase its population, and therefore since elks and mule deers feed on all the plants that you can find in that pyramid, the population of all plants will decrease since there will be more elks and mule deers to feed

What might cause the population of trees and grasses increase in this food web?

Explanation:

As you can see, if the hunting of grey wolves becomes unrestricted the population of grey wolves would decreased, this means that the natural predator for Elks and mule deer will be diminished, which means that not enough Elks and mule deers will be eaten, this would increase its population, and therefore since elks and mule deers feed on all the plants that you can find in that pyramid, the population of all plants will decrease since there will be more elks and mule deers to feed.

answer; i believe the correct answer is (a)0