The answer to this question is D. Perceptions; Beliefs.
Hallucinations are perception or distortion, it isn't really there, it can be an auditory or visual hallucination, or it is a morphed object in the room.
For example, you just started a new medication, and now you see shadow figures looming in the corner of your room, or you see ants on the floor. This is because of the effects of the meds, they are distorting your perception.
Another example could be your sister just died and you are in the denial stage of grief, you believe that "she can't be dead". You might begin to hallucinate your sister, whether in the corner of your eye or to hear her voice, as is associated with the intense and psychologically straining belief that she is still alive.
Therefore, the answer is D. Perceptions; beliefs.