Any source information that's used within the body of an essay a. must be included in parenthetical citations and on the works cited page. b. must be included in parenthetical citations only. c. must be included in a direct quotation. d. must be included in the works cited page only.

I would have to say A is the correct answer. Usually when you have sources coming from a book or the internet, you have to cite the source after you state it in your text and then also in the work cited. For example:

Monkey's are crazy and act like humans. They are the closest thing relatable to humans, hence why they do the same things we do. It really is a game of "Monkey See, Monkey Do (Monkey 101 p 15-19)"

Work Cited Page:

"Monkey 101," Monkey's Anonymous. 1956, pg. 15-19

When readers see the works cited page, they use the information found to refer back to your text and also to make sure that your citations are real. If I were to search for the citation that I made up, the chances of me actually finding a book called "Monkey 101" with the exact phrase "Monkey See, Monkey Do" is slim to none. Please excuse my crazy example though, and please do not hold my citation right above to the correct format. I just threw the example together. But I hope this helps!