The scenario that best describes an effect of the diffusion of U.S. culture is:
A person in Paris, France, takes their date to a fast-food restaurant for dinner.
This scenario illustrates the spread of American fast-food culture to other countries, which is a direct effect of cultural diffusion originating from the United States. The other options describe different cultural exchanges or influences but do not specifically highlight the diffusion of U.S. culture in the same way.