Your answer would be... B. The climate on Earth has changed over time.
Can you explain the first part a little more
I believe the answer is D, Cells get energy by taking in nutrients from food. Correct me if I'm wrong.
A. Consumers cannot produce their own food source so they have to eat other animals.
C. Rhizobia bacteria "prepare" the atmospheric nitrogen and make it useful for the plant.
Hope it helped,
Happy homework/ study/ exam!
