Answer:
a. The growing fear by white Americans who felt the Chinese presence would lead to unemployment.
Step-by-step explanation:
The golden rush in California attracted many Chinese laborers since thre late 1840s. After 1850, some 20,000 arrived each year. The Chinese laborers worked very hard under terrible conditions in mining and other jobs, and often for minimun wages. By 1880, there were 100,000 Chinese males in California.
Because of their attitude, they were the main labor force hired in railway construction and other hard jobs. White workers, many of them Irish, were angry because of this situation. They felt cheated and jealous. Racist and xenophobia flourished, often with violent attacks on the Chinese. As it has happened in other period of American history regarding immigrant groups, Chinese immigrants were seen as the origin of economic problems and of falling wages.