The most appropriate answer is D. Addams realized that individual efforts were futile if the government did not support them.
Jane Addams' experience in the Settlement House Movement, particularly through her work at Hull House in Chicago, made her acutely aware of the broader social issues affecting immigrants and the urban poor. She recognized that, while her individual efforts in the community were valuable, large-scale change required government intervention and policy reform. This understanding motivated her to engage more deeply in national politics and reform movements, advocating for social justice, women's suffrage, and peace.