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.
The answer would be d). These words all indicate that it is the protagonist who is speaking.
Answer:
Commas! They are used to separate ideas from each other, or be used in place of "and".
