Iron exhibits bcc structure at room temperature. Above

900º  C It transforms to fcc structure. the ratio of density of iron at room temperature to that at 900 º  C (assuming molar mass and atomic radii of iron remains constant with temperature ) is

a. √3 /√2

b. 4 √3/ 3 √2

c. 3 √3/4 √2

d. 1/2

Ans. c