I don’t understand what you mean by police girl offficer???
It helps develop the theme because with the teacher being strict Kevin no longer tries to get answers from his father and listens to the teacher and Kevin learns from it.
Zaroff values human life differently than most people. Without human life, he wouldn't have his ultimate prey to hunt. But that is the extent of the value that Zaroff places on human life. To Zaroff, a human isn't that much different than any other animal species that he hunts. Zaroff states that the one thing that humans possess that no other animal does is the ability to reason.
Hope this helps.
Please do not take my word on this because i am no 100% sure but i think it is B because he is using a metaphor to compare his life to crystal stairs.