using fur to trap air for warmth cracking open clams with a rock nursing its young for six months closing its ears under water
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which sea otter behavior is learned?
Possibilities:
- using fur to trap air for warmth
- cracking open clams with a rock
- nursing its young for six months
- closing its ears under water

cracking open clams with a rock