Why Does It Take More Than a Week Before a Mosquito

Why does it take more than a week before a mosquito just 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) Yellow fever is caused by a protozoan.It must develop from the sporozoite form into the mature form to become infectious,and this takes time.
D) The virus multiplies in the gut of the mosquito,but then needs to migrate to the proboscis (biting nose) of the animal in order to infect a new human being after a new bite.This migration takes time.