Chinese immigrants to the West:

(a) were exclusively single men, particularly after the Civil War.
(b) concentrated primarily in the Pacific Northwest, where lumber and fishing jobs were plentiful.
(c) grew to several million in number by the 1890s, due to the absence of federal immigration quotas.
(d) worked in shoe and cigar factories in western cities.
(e) were exclusively women working as domestics.

A. They were exclusively single men, particularly after the civil war.

Explanation: The migration of Chinese to US started far back middle of 19th century. Throughout the first half of the 19th century, Chinese manual laborers (predominately men) migrated to the West Coast, where they found employment in agriculture, mining, railroad construction, and other low-skilled jobs. In response to negative public sentiments and organized labor lobbying, Congress in 1882 passed the Chinese Exclusion Act, the first legislation aimed at excluding certain foreigners based on their origin.