A unlawfully locks B in a room. B has a duplicate key in his pocket by which he can open the door from inside and come out. But B forgets about the key and, as a result, remains locked for two hours. B then remembers that he has a duplicate key and opens the door and comes out. A is

liable for false imprisonment because he acted unlawfully

not liable for false imprisonment because B had a duplicate key by which he could have opened the door and come out

liable for false imprisonment because B had forgotten that he had a duplicate key

not liable because B’s forgetfulness was responsible for B remaining in the room