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 delusions" are seen in: \nSelect and explain. \nA. Endogenous depression, B. Dysthymia, C. Cyclothymia, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Endogenous depression', 'role': 'assistant'}]