This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intellectual disability, communication, autism, and ADHD, Subject name: Psychiatry
Severe mental retardation is - 
Select and explain. 
A. 50-70, B. 35-50, C. 20-35, D. <20
C: 20-35
Answer: C: 20-35 
Explanation: Ans is 'c' i.e. 20 - 35 o Normal IQ - 90-109;o Borderline IQ - 70-89;o Mild mental retardation IQ - 50-69;o Moderate mental retardation IQ -35-49;o Severe MR IQ - 20-34;o Profound MR IQ - 0-19.