for several weeks the function f(x)=3(4)^x represented the number of birds infected with an illness for x weeks after the birds first became sick. how did the number of sick birds change every week?

A. the number increased by 4 every week
B. the number increased by 3 every week
C.the number quadrupled every week
D. the number increased by a factor of 4 every week

D. the number increased by a factor of 4 every week

This can be seen from the function f(x) = 3(4)^x, where the base of 4 represents a factor of increase every week.