Which type of story is usually passed down from generation to generation?

The correct answer is folklore. Folklore encompasses traditional stories, legends, and tales that are often shared orally across generations within a culture. These stories typically reflect the values, beliefs, and customs of the community, making them an integral part of their cultural heritage. As they are passed down, folklore can evolve and adapt, but the essence of the stories remains tied to the traditions of the people who tell them.

Mythology generally refers to a specific set of myths that are linked to particular cultures and often explain natural phenomena or historical events, but it is not as broad as the term folklore. An autobiography is a narrative that records a person's own life and experiences, while historical fiction combines fictional elements with historical settings or events, focusing on storytelling rather than the oral traditions inherent in folklore. Thus, folklore is the most fitting term for stories that are traditionally handed down over the years.