need to consume plant matter. use plants for shelter. need carbon dioxide released by plants. consume other animals that eat plants.
I gave my students this multiple choice question: The best explanation of why carnivores are dependent on plants is because they

Only one answer is correct among these 4 choices:
- need to consume plant matter.
- use plants for shelter.
- need carbon dioxide released by plants.
- consume other animals that eat plants.

Could you tell me which one is correct?

consume other animals that eat plants.