A prisoner is facing three doors. He is told that behind one of them, there is a lady, and behind the other two there are tigers. The sign on the door of the room containing the lady is true. At least one of the other signs is false, maybe both.
The signs say
Room I A tiger is in room II
Room II A tiger is in this room
Room III A tiger is in room I
Assuming that the prisoner gets eaten immediately when opening the door to a room containing a tiger, and moreover assuming that he wants to keep alive, which door should he open?