Answer: A. The author explores human psychology by showing how little remorse both narrators have.
Both narrators in this excerpt have just commited a horrible act. However, the thing that makes them particularly similar is the fact that they do not seem to exhibit remorse. Their attitude is calculating, and instead of being upset about what they just did, they are concentrated on the future and the task ahead. This lack of remorse and emotion is a powerful theme, and through it the author invites us to analyze the complexity of human psychology and human nature.