The legal term for someone who did not know right from wrong when he or she committed a crime is:

The correct answer is B. insanity.

Insanity is a legal term that refers to a state where an individual is unable to distinguish right from wrong due to a severe mental disorder at the time of committing a crime. This concept often serves as a defense in criminal cases, indicating that the person lacked the mental capacity to understand the nature of their actions or the legality of those actions.