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': "Which disease doesn't require chemoprophylaxis? \nSelect and explain. \nA. Measles, B. Conjunctivitis, C. Cholera, D. Malaria", 'role': 'user'}, {'content': "Answer: A \nExplanation: Measles prevention is only by immunisation and vaccination. No chemoprophylaxis(Ref.PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 21st Edition page no.136)", 'role': 'assistant'}]