Answer:
The answer is B.
Step-by-step explanation:
A lot of people went to California during the Gold Rush, but not many people found any gold. When most people got there, there wasn't any gold left because other people had already gotten it and there wasn't much to begin with. That's also why there are a lot of ghost towns in California: the people who came to find gold didn't find any, got poor, and had to leave.
Also, you aren't dumb. I hope this helps! ☺