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
True about epidemiology of influenza - 
Select and explain. 
A. Asymptomatic seen rarely, B. Incubation period 10-12 hrs, C. Pandemic rare, D. All ages sex are equally affected
D: All ages sex are equally affected
Answer: D: All ages sex are equally affected 
Explanation: Influenza is characterised by sudden onset of chills,malaise, fever, muscular pains and cough Influenza A strain is pandemic IP period l8 to 72 hours Affects all ages andboth sexes Reference : Park&;s Textbook of preventive and social medicine, 24th edition.Pg no. 163,164