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': 'Class II cavity preparation for amalgam restoration in\ndeciduous teeth requires: \nSelect and explain. \nA. More buccolingual extension, B. More nnesiodistaL extension, C. More gingival, D. More cervical', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]