by protecting deer from other predators by controlling the deer population by decreasing diversity within the herd by protecting the deer from disease
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Deer provide food for wolves. How does this relationship also benefit the deer herd?
Possibilities:
- by protecting deer from other predators
- by controlling the deer population
- by decreasing diversity within the herd
- by protecting the deer from disease

by controlling the deer population