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
IQ of 15 is which grade of mental retardation ? 
Select and explain. 
A. Mild, B. Moderate, C. Borderline, D. Profound
D: Profound
Answer: D: Profound 
Explanation: Ans. is.'d' i.e., Profound Category IQ Normal intelligence > 90 Borderline intelligence 70 - 89 Mental retardation Mild MR Moderate MR Severe MR Profound MR 50 - 69 35 - 49 20-34 0-19