Answer:
Hi!
The answer to your question would be option D. Your source cards.
Step-by-step explanation:
The most helpful tool to use when composing a works cited page are your source cards. As we know, a works cited page is a list of works that you referenced in the body of your paper. On the other hand, a source card contains the necessary information to cite a source, such as the author's name, title of the work, publication, URL of the website, etc.
This is why a source card would be the most helpful tool to use when composing a works cited page.