Would you be able to kill a person?

At first, I thought I should seriously reconsider before voting, but since the option "Of course, I always do" seemed strange and unserious, I chose it out of sheer contrariness. But seriously, I think I could kill someone if it was REALLY necessary. And then thoughts arise about Dostoevsky's immortal work, Crime and Punishment. Why did Raskolnikov feel such remorse after doing what he thought was a *good deed*? In principle, everything was well-reasoned, and I still don't understand what tormented him so much.