Iron crystallizes in several modifications, At about 910°C, the body centred α-form undergoes transition to the face centred cubic γ-form. Assuming that the distance between nearest neighbours is same in the two forms at the transition temperature. Calculate the ratio of density of γ-iron to that of α-iron at the transition temperature.

A. 2.087
B. 1.087
C. 4.06
D. 5.09