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
Disease highly transmitted during the incubation period is - 
Select and explain. 
A. Brucellosis, B. Cholera, C. Measles, D. Pertussis
D: Pertussis
Answer: D: Pertussis 
Explanation: 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.