Read the passage. Then answer the question.
Early prospectors found gold by panning for it in rivers. They also found it near the surface using a pick and an axe. Some gold seekers did strike it rich, either by luck or hard work. However, by 1850, most of the surface gold was already found and the gold rush was almost over. In that same year, California became a state.
When did California become a state?
A. in 1848
B. in 1850
C. after the gold seekers left
D. when the gold rush started in California