If the Radius of Circle B Is Twice the Radius $\infty$

If the radius of circle B is twice the radius of circle A, and the area of a circle is proportional to the radius squared (A $\infty$ r²) , then the ratio of the area of circle B to that of circle A is:

A) 4
B) 0.5
C) 0.25
D) 2
E) 1.414