eating small fish swimming in salt water balancing a ball on its nose breathing though its blowhole
I gave my students this multiple choice question: Which of these behaviors does a dolphin learn?

Only one answer is correct among these 4 choices:
- eating small fish
- swimming in salt water
- balancing a ball on its nose
- breathing though its blowhole

Could you tell me which one is correct?

balancing a ball on its nose