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': "During oral examination of a 57-year-old-man, a large keratotic patch that covers the entire palate is noted. Some 'Red Spots' are also seen in the patch. The patient most likely is a: \nSelect and explain. \nA. Pipe smoker, B. Cigar smoker, C. Snuff chewer, D. Tobacco chewer", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]