This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Organic Mental Disorder, Subject name: Psychiatry
[{'content': 'IQ of 15 is which grade of mental retardation - \nSelect and explain. \nA. Mild, B. Moderate, C. Borderline, D. Profound', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., ProfoundCategoryIQNormal intelligence> 90Borderline intelligence70 - 89Mental retardationMild MR50 - 69Moderate MR35-49Severe MR20-34Profound MR0-19", 'role': 'assistant'}]