I just took a test in school today. What question was I asked?

Question I was asked: Which of the following is an example of how insects are beneficial to humans?

I just took a test in school today. What question was I asked?

Question I was asked: What is a large buildup of moving ice and snow called?

I just took a test in school today. What question was I asked?

Question I was asked:
A factory in Japan had been dumping mercury into Minamata Bay. Certain microorganisms in the water were able to change the mercury into a form that the plankton could use. Which most likely happened next?