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': 'The main purpose of covering the retromolar pad area is \nSelect and explain. \nA. Stability, B. Retention, C. Support, D. Contraction', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]