Question

The purpose of a parenthetical citation is to

provide complete citation information for the source.
use a signaling phrase to recognize the author or type of source.
refer the reader to the source information on the Works Cited page.
identify expert testimony when it is used in an essay.

Answer 1

C: "refer the reader to the source information"
A is wrong, because complete information is in the works cited.
B is wrong, because you aren't changing the text at all, just adding a parenthetical note. If you wanted to recognize the author, you'd do it in-text (e.g. "According to Freud ...").
D is not exactly right, because, again, if you wanted to appeal to an expert, you'd typically do that in-text, whereas the citation is meant to prove that the expert really said what you're claiming.