The answer is A, because the protagonist is the main character, and that's what Rider is. The other answers don't really make sense in terms of the role he plays in the story.
Hope I helped!
Answer:
Hamlet doesn't kill Claudius at this point because he believes that Claudius is praying. He says that killing the king NOW would be "hire and salary, not revenge!" He simply cannot send Claudius to heaven, where he would surely go were he killed just after praying and purging his sins.
Explanation: