<s>[INST] context: Influenza Incubation period is the time elapsed between exposure to the pathogenic organism and when symptoms and signs are first apparent. Incubation period of some pathogens are: Varicella (Chickenpox) - usually 14 to 16 days Measles (Rubeola) - usually 10 days from exposure to onset of fever, and 14 days to appearance of rash Rubella (German Measles) - 2 to 3 weeks; usually 18 days Mumps - 2 to 3 weeks; usually 18 days Influenza - 18 to 72 hours Diphtheria - 2 to 6 days Peussis - usually 7 to 14 days, but not more than 3 weeks Meningiococcal Meningitis - usually 3 to 4 days. but may vary from 2 to 10 days Tuberculosis - the time from receipt of infection to the development of a positive tuberculin test ranges from 3 to 6 weeks, and thereafter, the development of disease depends upon the closeness of contact, extent of the disease and sputum positivity of the source case and host parasite relationship. Thus the incubation period of tuberculosis varies from weeks, months or years. Polio - usually 7 to 14 days Hepatitis A - 15 to 45 days (usually 25 to 30 days) Hepatitis B - 45 to 180 days Hepatitis C - 40 to 120 days Cholera - from few hours up to 5 days, but commonly 1- 2 days Typhoid - usually 10 - 14 days, but it may be as sho as 3 days or as long as 3 weeks depending on the dose of bacilli ingested. Amoebiasis - 2 to 4 weeks Ascariasis - about 2 months Filariasis - 8 to 16 months Rabies - highly variable from 4 days to many years but usually 3- 8 weeks Yellow fever - 3 to 6 days (6 days recognized under International Health Regulations) [/INST] question: Shoest incubation period is seen in: | options: A: Hepatitis A B: Hepatitis B C: Rubella D: Influenza | answer: D </s>