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: Social & Preventive Medicine
A person with IQ of 55 is 
Select and explain. 
A. Mild mental Retandation, B. Moderate Mental Retandation, C. Severe Mental Retandation, D. Very Severe Mental Retandation
A: Mild mental Retandation
Answer: A: Mild mental Retandation 
Explanation: None