This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'All of the statement regarding measles are true except- \nSelect and explain. \nA. Rash appears first on leg, B. Koplik spot are seen on the buccal mucosa, C. Long term complication may be seen in form of SSPE, D. Caused by RNA virus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Rash begins behind the ear and spread rapidly in a few hours over the face and neck, and extends down the body taking 2 to 3 days to progress to the lower extremities. Ref: PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition , Page:148', 'role': 'assistant'}]