Answer:
I believe the answer is C. many mining towns were abandoned when miners moved to new mines.
Step-by-step explanation:
The name given to mining towns that were abandoned after all the gold was mined from the rivers and streams was ghost towns. These towns once were full of people that were there to exploit raw materials such as gold of coal. After that happened, people left the locations and headed to another place to find more raw materials. That is why ghost towns look abandoned. There are remains of houses and sone buildings, but the place looks deserted.
I hope I helped, please correct me if I'm wrong!