The areas of the two spheres are in the ratio 1: 4. The ratio of their volume is?
A. 1:4
B. 1:16
C. 1:8
D. 1:64
4πr12 : 4πr22 = 1 : 4
r1 : r2 = 1 : 2
4/3 πr13 : 4/3 πr23
r13 : r23 = 1 : 8