This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
[{'content': 'All of the following are features of hallucinations, except : \nSelect and explain. \nA. It is independent of the will of the observer, B. Sensory organs are not involved, C. It is as vivid as that in a true sense perception, D. It occurs in the absence of a perceptual stimulus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Hallucination is a sensory perception without external stimulation of the relevant sensory organ. Though there is no stimulation of sensory organs, hallucinations appear to arise from one of the external sensory organ.', 'role': 'assistant'}]