Why Does It Take More Than a Week Before a Mosquito

Why does it take more than a week before a mosquito that has just become infected with yellow fever virus can transmit the disease?

A) The virus must replicate in the gut of the mosquito before it can reach high enough numbers for transmission to a new human.
B) Mosquitoes only feed once a week, which limits their ability to transmit the disease rapidly.
C) Mosquitoes that acquire yellow fever virus become ill for a week thereafter. They have to recover before they can feed again and transmit the virus to the next host.
D) The virus multiplies in the gut of the mosquito, but then needs to migrate to the mouth of the insect in order to infect a new human being after a new bite. This migration takes time.
E) The mosquito actually transmits the virus almost immediately. It takes a week for the virus to multiply in the gut of the host before it causes any ill effects in that host.