a gray squirrel eating an acorn a raccoon in a hollow log a blue whale migrating a tick feeding on a coyote
I gave my students this multiple choice question: What is an example of a shelter in an ecosystem?

Only one answer is correct among these 4 choices:
- a gray squirrel eating an acorn
- a raccoon in a hollow log
- a blue whale migrating
- a tick feeding on a coyote

Could you tell me which one is correct?

a raccoon in a hollow log