This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Psychoanalysis, Subject name: Psychiatry
[{'content': 'Which of the following is not a neurotic defense mechanism? \nSelect and explain. \nA. Isolation, B. Regression, C. Reaction formation, D. Undoing', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Regression is an immature defense mechanism. Rest all are neurotic defense mechanism. Eg of neurotic defense mechanism - Displacement Repression Rationalization Reaction formation Intellectualization Isolation of affect Undoing Aim inhibition', 'role': 'assistant'}]