I found the options online. I will state them and provide the answer.
OPTIONS
A. find out what the prospective employer has to offer.
B. outline your value to a prospective employer.
C. accompany your portfolio.
D. remind the prospective employer of your recent interview.
ANSWER.
A letter of application is intended to outline your value to a prospective employer (option B) It is also known as a cover letter. It might be considered a job application which you send together with your CV to provide additional info about you.