Final answer:
The Anti-Imperialist League opposed American expansionism and the subjugation of other nations, believing it contradicted American principles of democracy and freedom.
Step-by-step explanation:
The basic criticism of empire building by the Anti-Imperialist League was that such practices were antithetical to the American principles of democracy and freedom. Notable figures such as Jane Addams and Mark Twain were part of this league and voiced their concerns that empire building would lead to the subjugation and domination of other peoples, which they saw as a moral and political contradiction to the values the United States claimed to uphold. The correct answer to the student's question is that the Anti-Imperialist League opposed American expansionism and the subjugation of other nations, making option (c) the correct choice.