Final answer:
The correct Works Cited entry in MLA format for a book with one author from the provided options is Entry B.
Step-by-step explanation:
To correctly cite a book with one author in a Works Cited page in MLA format, the correct entry among the options provided is Entry B: Haines, Leah. Really Bad Ideas That People Actually Believed. Waverly, 2005. This format includes the author's name, the title of the book in italics, the publisher, and the year of publication, following the MLA guidelines.