This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Social science, Mental health & Genetics, Subject name: Social & Preventive Medicine
IQ in moderate mental retardation - 
Select and explain. 
A. 90-70, B. 70-50, C. 50-35, D. 35-20
C: 50-35
Answer: C: 50-35 
Explanation: WHO classification of Mental retardation(MR) mild MR...IQ 50-70 moderate MR ...35-49 severe MR..IQ 20-34 profound MR...IQ under 20 ref; (page no;582) 23rd edition of PARK&;s textbook of Preventive and Social medicine