Two circular mild steel bars A and B of equal lengths have diameters 2 cm and 3 cm respectively. Each is subjected to a tensile load of magnitude T. The ratio of elongations of the bars $$I_A / I_B$$ is

A

$$\frac {2}{3}$$

B

$$\frac {5}{8}$$

C

$$\frac {4}{9}$$

D

$$\frac {2}{5}$$