The statement that is true regarding women's roles in Europe and the United States during the 19th and 20th centuries is:
Poor women worked outside of the home.
During this time, many poor women engaged in various forms of labor, such as factory work, domestic service, and other types of employment, to support themselves and their families. Upper-class women, on the other hand, were more likely to be confined to domestic roles or engaged in social functions rather than working in factories or mills. Therefore, the other statements either misrepresent the historical context or are inaccurate.