Explanation:
Appendix refers to additional material at the end of a book, often containing supplementary content like references, notes, or in this case, traditional folktales.

Index is a list of topics or subjects in a book, usually found at the back but is not additional material like an appendix.

Insertion means something added, but it doesn’t specifically refer to additional content at the end of a book.

Information is too vague and doesn’t refer to supplementary content.

Overview refers to a summary, which doesn't match the context of additional content in the book.