The sentence gives you two words to help you describe what this outfit might look like: elaborate and foolish. You know to immediately throw out subdued (or simple) and demure (or modest) because those support foolish and elaborate. Trite means overdone, so that word doesn’t have much relevance here. Rustic means unpolished and natural which also doesn’t support the excessiveness of the outfit. Foppish (D) means being foolishly vain about the way one is dressed, so it fits perfectly.