OPTIONS: I. sea urchins II. squids III. Jellyfish IV. bioaerosols V. tunicates VI. most cephalopods VII. mussels VIII. tiny polyps
Q: Fact 1: Microscope is used to see small things by biologists by making them appear bigger. Fact 2: Bioaerosols are extremely small living organisms or fragments of living things suspended in the air. Given the two facts above, what do biologists use a microscope to see by making them appear bigger?
A:
IV.