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
[{'content': 'An IQ between 50 & 70 would be classified as what kind mental retardation – \nSelect and explain. \nA. Mild, B. Moderate, C. Severe, D. Borderline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The WHO classification of mental retardation is based on the concept of IQ and includes the following categories:', 'role': 'assistant'}]