You are presented with the quiz "What do exoskeletons secreted by corals do?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "many corals secrete an exoskeleton that builds up to become a coral reef" and "to fisherfolk, coral reefs are homes to fish that are waiting to be caught". 

So, what's the best answer to the question?


 

    Give homes to fish       