which example is most likely from a cover letter ?

Answer:
Option A
Explanation:
A cover letter is attached to a resume for the applicant to introduce himself/herself and tell why the manager would pick him/her to get the job.
It contains a overview of his or her work experience most related to the job posting.
Option A would be your best answer because it tells that the narrator had experience and he/she also says that he/she would be a good person for a lead counselor.