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
Mild mental retardation is characterized by 
Select and explain. 
A. IQ : 90 - 109, B. IQ : 70 - 89, C. IQ : 50 - 69, D. IQ : 35 - 49
C: IQ : 50 - 69
Answer: C: IQ : 50 - 69 
Explanation: Normal : 90 - 109.
Borerline : 70 - 89.
Mild : 50 - 69.
Moderate : 35 - 49.
Severe : 20 - 34.