This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mental Health, Subject name: Social & Preventive Medicine
Mental retardation is defined if IQ is below:- 
Select and explain. 
A. 60, B. 70, C. 80, D. 90
B: 70
Answer: B: 70 
Explanation: Normal IQ 70 or above. Mild mental retardation = 50-70 Moderate mental retardation = 35-49 Severe mental retardation = 20-34 Profound mental retardation = <20.