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: Surgery
[{'content': 'Which is the best definition of a delusion? \nSelect and explain. \nA. Fixed false belief, B. Perceptual misrepresentation of a sensory image, C. Perceptual representation of a sound or an image not actually present, D. Pathological self preoccupation', 'role': 'user'}, {'content': "Answer: A \nExplanation: Fixed false belief A delusion is a fixed, false belief that is not in keeping with a patient's cultural background. The perceptual misrepresentation of a real sensory image is an illusion. The perceptual representation of a sound or an image that is not actually present is a hallucination. A pathological self-preoccupation is the definition of egomania. A dissociative fugue is a state in which patients travel away from their homes or work and assume new identities or occupations while forgetting impoant aspects and details of their former lives.", 'role': 'assistant'}]