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: Pathology
[{'content': 'Most common site of oral leukoplakia is \nSelect and explain. \nA. angle of mouth, B. cheek mucosa, C. Soft palate, D. Gingiva', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]