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': 'Which of the following works on relaistic principle according to structural theory of mind \nSelect and explain. \nA. Id, B. Ego, C. Preconscious, D. Super ego', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Id works on pleasure principle\nSuperego works on morality principle\nEgo works on reality principle & balances between Id & superego.', 'role': 'assistant'}]