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: Dental
[{'content': 'A patient of 8years-old attends your clinic he has class\nI incisor relation upper and lower incisors shows slight crowding. Right upper and left lower primary first molars\nrecently extracted due to caries line of treatment is \nSelect and explain. \nA. Extraction of Left upper and right lower primary first molars to relieve crowding, B. Extract all primary canines to relive crowding, C. Fix space maintainers, D. Await until premolar erupt', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]