The answer is A. The quality of the parent-child relationship.
The mass emigration, which occurred from the 19th century to 1949, was mainly caused by wars and starvation in mainland China, economic issues abroad such as the California gold rush in 1849, as well as problems resulting from political corruption.
Explanation:
America's involvement in World War II had a significant impact on the economy and workforce of the United States. American factories were retooled to produce goods to support the war effort and almost overnight the unemployment rate dropped to around 10%.