Correct Option: B

blameless (Adjective) : innocent ; doing no wrong ; free from responsibility for doing something bad
culpable (Adjective) : responsible and deserving blame for having done something wrong
defendable (Adjective) : capable of being protected from attack
careless (Adjective) : casual ; not giving enough attention and thought to what you are doing
irresponsible (Adjective) : not thinking enough about the effects of what one does