Which Statement About the Problem of Other Minds Is TRUE

Which statement about the problem of other minds is TRUE?

A) The "consciousness meter" of anaesthesiologists has produced tremendous insight into the conscious experiences of other minds.
B) You can quickly assess if your roommate is or is not an unconscious zombie by asking her how she feels.
C) By studying another person in tremendous detail,psychologists ultimately will be able to truly know what it is like to be that person.
D) It cannot be proven if anyone else besides you even experiences consciousness.