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': "Nihilistic ideas are seen in -a) Simple schizophreniab) Paranoid schizophreniac) Cotard's syndromed) Depressione) Body dysmorphic disorder \nSelect and explain. \nA. cd, B. bc, C. bd, D. ac", 'role': 'user'}, {'content': "Answer: A \nExplanation: Nihilistic delusion is false belief that oneself, other or the world is non-existent or about to end. It is seen in severe depression.\nIf nihilistic delusions are accompanied by ideas concerning bodily function failure, the syndrome is called Cotard's syndrome.", 'role': 'assistant'}]