Select the true statements about yellow fever.
1. Transmitted by Aedes.
2. Incubation period is 10-14 days.
3. It is caused by Flavivirus.
4. Incidence is increased by humidity.

Correct option is D

Yellow fever is a viral hemorrhagic disease transmitted by mosquitoes.
· (1) Transmitted by Aedes – Correct, as Aedes aegypti is the primary vector of yellow fever.
· (2) Incubation period is 10-14 days – Incorrect, as the actual incubation period ranges between 3-6 days.
· (3) It is caused by Flavivirus – Correct, as yellow fever is caused by the Yellow fever virus, a member of the Flavivirus genus.
· (4) Incidence is increased by humidity – Correct, as higher humidity levels favor mosquito breeding, leading to higher transmission rates.
Explanation of Other Options:
· (a) 1 and 2 only – Incorrect, as statement 2 is false and statement 3 should be included.
· (b) 3 and 4 only – Incorrect, as statement 1 (Aedes transmission) is also true.
· (c) 1, 2, and 3 only – Incorrect, as statement 4 is also true.
· (d) 1, 3, and 4 only – Correct answer, as all these statements are factually correct.