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': 'cutaneous maculopapulary rash of the head and neck preceded by small ulcers in the buccal mucosa would suggest which of the following? \nSelect and explain. \nA. Primary herpes simplex infection, B. Rubeola, C. Varicella, D. Primary syphilis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The maculopapulary rash of rubeola (measles) is preceded by the herald sign of Koplick’s spots (punctate ulcers of the buccal mucosa)', 'role': 'assistant'}]