The answer is facts, an objective statement does not include opinion.
1) D.
2) A. (??)
3) B.
4) "Some of these nouns are pretty amusing."
Answer:
When writing a restrictive clause, introduce it with the word "that" and no comma. However, if the subject is or was a human being, use "who" to introduce the clause. When talking about people in defining (restrictive) relative clauses, who is preferred to that.
Answer:
Personified Object: The Frantic Drum
Human Quality: Echoing
Explanation: