I think the blank is an audience, because if your writing a PERSUASIVE essay, your trying to persuade a specific audience to agree with you on an opinion or trying to complete a certain action, so D makes the most sense, in my mind at least
Synonyms of dis-simulation or dissimulate are to disguise, cover up, hide, conceal, or being hypocritical
It would seem so.
I would choose the same answer you chose