For many years it was common in the United States to associate Chinese Americans with restaurants and laundries. People did not realize that the Chinese had been driven into these occupations. The first Chinese to reach the United States came during the California Gold Rush of 1849. Like most of the other people there, they had come to search for gold. In that largely unoccupied land, the men staked a claim for themselves by placing marks in the ground. However, either because the Chinese were so different from the others or because they worked so patiently that they sometimes succeeded in turning a seemingly worthless mining claim into a profitable one, they became the scapegoats of their envious competitor. They were harassed in many ways. Often they were prevented from working their claims; some localities even passed regulations forbidding them to own claims. The Chinese, therefore, started to seek out other ways of earning a living. Some of them began to do the laundry for the white miners; others set up small restaurants. (There were almost no women in California in those days, and the Chinese filled a real need by doing this "woman’s work".) Some went to work as farmhands or as fishermen. In the early 1860’s many more Chinese arrived in California. This time the men were imported as work crews to construct the first transcontinental railroad. They were sorely needed because the work was so strenuous and dangerous, and it was carried on in such a remote part of the country that the railroad company could not find other labourers for the job. As in the case of their predecessors, these Chinese were almost all males; and like them, too, they encountered a great deal of prejudice. The hostility grew especially strong after the railroad project was complete, and the imported labourers returned to California—thousands of them, all out of work. Because there were so many more of them this time, these Chinese drew even more attention than the earlier group did. They were so very different in every respect: in their physical appearance, including a long "pigtail" at the back of their otherwise shaved heads; in the strange, non-Western clothes they wore; in their speech (few had learned English since they planned to go back to China); and in their religion. They were contemptuously called "heathen Chinese" because there were many sacred images in their houses of worship. When times were hard, they were blamed for working for lower wages and taking jobs away from white men, who were in many cases recent immigrants themselves. Anti-Chinese riots broke out in several cities, culminating in arson and bloodshed. Chinese were barred from using the courts and also from becoming American citizens. Californias began to demand that no more Chinese be permitted to enter their state. Finally, in 1882, they persuaded Congress to pass the Chinese Exclusion Act, which stopped the immigration of Chinese labourers. Many Chinese returned to their homeland, and their numbers declined sharply in the early part of this century. However, during the World War Ⅱ, when China was an ally of the United States, the exclusion laws were ended; a small number of Chinese were allowed to immigrate each year, and the Chinese could become American citizens. In 1965, in a general revision of our immigration laws, many more Chinese were permitted to settle here, as discrimination against Asian immigration was abolished. Chinese Americans retain many aspects of their ancient culture, even after having lived here for several generations. For example, their family ties continue to be remarkably strong (encompassing grandparents, uncles, aunts, cousins and others). Members of the family lend each other moral support and also practical help when necessary. From a very young age children are imbued with the old values and attitudes, including respect for their elders and a feeling of responsibility to the family. This helps to explain why there is so little juvenile delinquency among them. The high regard for education which is deeply embedded in Chinese culture, and the willingness to work very hard to gain advancement, are other noteworthy characteristics of theirs. This explains why so many descendants of uneducated labourer have succeeded in becoming doctors, lawyers, and other professionals. (Many of the most outstanding Chinese American scholars, scientists, and artists are more recent arrivals, who come from China’s former upper class and who represent its high cultural traditions. ) Why would so many Chinese Americans in California be involved in the occupations of restaurants and laundries in the 19th century

A. Because they were good at these jobs.
Because there were few women to do those jobs at that time.
C. Because of the prejudice and discrimination against the Chinese, they had no other choices.
D. Because they could not find gold in mines.