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

Question I was asked: Which tool is most responsible for preventing future pandemics of smallpox?

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

Question I was asked: A student climbs up a rocky mountain trail in Maine. She sees many small pieces of rock on the path. Which action most likely made the small pieces of rock?

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

Question I was asked:
Which best describes all unicellular organisms?