The sentence that is a correct example of an in-text citation is A.
Explanation:
An in-text citation is a reference made within the body of the text of an academic essay. In order to write an in-text citation, you should generally nclude the following information: the author's last name, the date of publication and the page number from which the quotation or paraphrase is taken, and the complete reference appearing in your works cited page at the end of your essay. This depends on the style and format you are following.
In this case, the name of the author apperars in the sentence itself, so it should not be included in the parentheses. The parentheses should only include the page(s) number, as sentence C illustrates.
