The purpose of a descriptive essay is to describe a person, place, or thing in such vivid detail that the reader can easily form a precise mental picture of what is being written.
So A is the answer hope this helps and let me know if it's right!
Do your research, explain your evidence thoroughly. Look over the rubric if you have one and make sure your hitting all of the points.
Use credible sources and justify your argument clearly through your thesis statement. Good luck on your essay