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': 'Forcheimer sign is seen in \nSelect and explain. \nA. Infectious monocucleosis, B. Scarlet fever, C. Rubella, D. Rubeola', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]