This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Organic Mental Disorders, Subject name: Psychiatry
[{'content': 'Organic mental disease is indicated by: \nSelect and explain. \nA. Incoherence, B. Delusion, C. Flight of idea, D. Perseveration of speech', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Perseveration of speech is suggestive of organic mental disorders. Few books are giving the answer as delusion which is completely wrong. Flight of ideas is seen in case of mania. Incoherence is formal thought disorder characteristic of Schizophrenia.', 'role': 'assistant'}]