Answer: A. Cover letter
Step-by-step explanation:
The element of the portfolio that this checklist best apply is the cover letter. The cover letter is a document that a job applicant will send along with his or
her resume in order to provide additional information with regards to the skills and experience that the person possesses and why the person is qualified for the position.
Since Antwon checks whether the content in the portfolio corresponds to the job requirements and also made sure that his role in creating each document in the portfolio is clear, this is a cover letter.