Hello! Please answer this question if you know how! Thanks!!

C. Doctors recommend 2-3 hours of exercise a week.

Explanation:

Facts are usually things which have concrete evidence or tend to have some form of data (without opinions most of the times) to support it.

Here A, B, D all have opinionated statements whereas, C lists out a fact well-known in medical and/or nation-wide communities.

fears about being blown up

martians or other types of aliens represent a unique fear as opposed to zombies. vampires and other types of monsters.   in most sci-fi stories, aliens come from other worlds and have different or more advanced technology.   abductions and experimentation on human bodies that involve these technologies, or the use of these technologies against human beings and the use of unknown "powers", are a type of fear that's different from that of other types of monsters.