Final answer:
The Chinese Exclusion Act of 1882 was primarily passed due to xenophobia and economic fears about Chinese immigrants taking jobs from American workers. It was the first law in U.S. history to explicitly ban a group based on race or ethnicity, and it added to a legacy of discrimination against Asian Americans.
Step-by-step explanation:
The social factor that contributed most to the passage of the Chinese Exclusion Act in 1882 was fear of unfamiliar Chinese customs and practices (A). It was a period characterized by intense xenophobia and the belief that Chinese immigrants were competitive threats to the employment market, particularly on the West Coast. Unlike option B, concerns about Chinese communism weren't relevant at that time, as communist ideologies were not yet widespread or influential during that era. Option C, the belief that Chinese immigrants needed protection against discrimination, is ironic, given that the act was itself discriminatory. Option D's reference to imperialism does not directly pertain to the motivation for the Chinese Exclusion Act.Anti-Chinese sentiment in the United States was chiefly fueled by economic concerns and racism. The rhetoric used to pass the Chinese Exclusion Act included depicting Chinese as 'imports' instead of immigrants, effectively dehumanizing them and inciting fears of job loss among American workers. The Act, by targeting Chinese laborers and later extended to other Asian immigrants, solidified discriminatory practices legally and socially. Furthermore, such legislation had a long-lasting impact on the perception and treatment of Asian Americans in the United States.In conclusion, xenophobia and economic competition were the most significant factors leading to the Chinese Exclusion Act of 1882. This act marked the first time the U.S. explicitly banned a group based on their race or ethnicity, setting a precedent for future immigration restrictions and contributing to a history of oppression against Asian communities in America.