Answer:
A. Someone who investigates what happened in the past
Step-by-step explanation:
Use elimination so I can tell you that it is not b. because historians don't study earthquakes that would be a geologist, and I don't think it would be D. so it would have to be either A. or C. I think it would be A. because a historian is somebody who is an expert or a student in history, and that's what I think it is. Hope this helps you :)