The correct answers are C. Readers question the narrator's interpretation of his motivation, and D. Readers fear what the narrator, giving into evil, will do next.
He is evidently distressed and deeply disturbed, but nevertheless, we are wondering if he tries to run away from his responsibility. People don't just turn from good to bad, and that is why we doubt his account and interpretation.
As for D, we feel suspense and expect something bad to happen, thanks to the narrator's description of his own state of mind.