4. What is a citation? any quotation or reference used in a research paper
a footnote giving additional information at the bottom of a page
a formatted reference to a source used in a research paper
a short listing of reference titles used in a research paper

any quotation or reference used in research paper.

A indication that the quote doesn't belong to you but the author.

Explanation:

For example for MLA writing, when you finish a quote, at the end of the sentence you add the first author's last name and page number.

They used a wagon that was departing at night, and they were in the hidden compartment in the bottom

I read this book when I was in 6th grade, I absolutely loved it lol.

Hope this helped :)