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: Social & Preventive Medicine
[{'content': 'Disease highly transmitted during the incubation period is - \nSelect and explain. \nA. Brucellosis, B. Cholera, C. Measles, D. Pertussis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Whooping cough is most infectious during catarrhal stage. The infective period may be considered to extend from a weak after exposure to about 3 weeks after the onset of the paroxysmal stage although communicability diminishes rapidly after the catarrhal stage.', 'role': 'assistant'}]