1. As Thanksgiving approaches, Martha sees many advertisements encouraging her to donate her time or money to help serve Thanksgiving dinner to the poor families in her community.

A. If Martha donates $20, is she acting in her own self-interest? Explain your answer.

B. True or False: If Martha donates two hours on Thanksgiving day to help serve food at the local community center, but doesn't donate any money, it doesn't cost her anything to help the poor families in her community. Explain your answer.

C. If Oscar donates $100, and Martha donates only $20, is Oscar behaving rationally? Explain your answer.