feed their young adapt to their environment attract a mate search for food
I gave my students this multiple choice question: A duck's feathers are covered with a natural oil that keeps the duck dry. This is a special feature ducks have that helps them

Only one answer is correct among these 4 choices:
- feed their young
- adapt to their environment
- attract a mate
- search for food

Could you tell me which one is correct?

adapt to their environment