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': 'All of the following are precancerous conditions except: \nSelect and explain. \nA. SLE, B. Peutz-Jeghers syndrome, C. Plummer-Vinson syndrome, D. Xeroderma pigmentosum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]