This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Dengue fever, all true except: \nSelect and explain. \nA. Is spread by the vector Aedes aegypti, B. Has an incubation period of 2-3 weeks, C. Is caused by a Flavivirus, D. Characteristically causes severe myalgia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Has an incubation period of 2-3 weeks.a. Dengue virus belongs to Flaviviridae. Two genera of medical importance in Flaviridae-b. Flavivirus: arthropod borne viruses; Dengue, Yellow fever, Japanese encephalitisc. Hepacivirus: non-arthropod borne; Hepatitis C virus.d. Vector for dengue- Aedes aegypti mosquito. Others- A. albopinctus, A. polynesiensis. These mosquitoes breed around human dwellings in uncovered water storage containers, vases, flower dishes, cans, etc. They shelter indoors and are day biters.e. Incubation, period - 5-8 days. All age groups & both sexes are affectedf. Saddle back fever (biphasic), severe headache and retro-orbital pain, muscle and joint pains (break bone fever), nausea, vomiting and rash are seen in dengue.', 'role': 'assistant'}]