A).
A supporter of immigration restrictions during the late 19th and early 20th centuries would most likely agree with the statement: "American culture is being destroyed by foreign influences."
During this time period, there was a significant increase in immigration to the United States, particularly from Southern and Eastern Europe. Many Americans were concerned about the cultural and ethnic diversity that these new immigrants brought, and feared that it would undermine traditional American values and ways of life. This fear led to the passing of several laws and policies that restricted immigration, such as the Immigration Act of 1924, which established strict quotas on the number of immigrants allowed into the country.