Final answer:
Jeff's preconceived ideas about Naia are an example of stereotyping or prejudice.
Step-by-step explanation:
Jeff’s preconceived ideas about Naia are an example of stereotyping or prejudice. Stereotyping is when someone makes assumptions or generalizations about a person or group based on limited information or preconceived notions. In this case, Jeff assumes that all vegans are protesting for animal rights, without considering Naia's personal reasons for being vegan.