The best answer is A.
although B and C are correct, they mostly miss the point of the sentence.
Answer:
1. Diaries, notebooks, letters. They hold the author's own words and are thus considered primary information.
2. Secondary information consists of autobiographies, poems, and text about the person. These are not from the person's eyes or perspective, instead, they are a retelling of their achievements. Hope this helps!
Assuming that the words what you wore to the party was the bold one, those are noun clause
That clause refer to an object which is the dress or the suit that the person being asked wore to the party
hope this helps
