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
A 16 year old male is found to have a mental age of 9 years on I.Q. testing. He has - 
Select and explain. 
A. Mild mental retardation, B. Moderate mental retardation, C. Severe mental retardation, D. Profound mental retardation
A: Mild mental retardation
Answer: A: Mild mental retardation 
Explanation: None