Volume of a cube of side ‘l’ and volume of a sphere of radius ‘r’ are equal. Both the cube and the sphere are solid and of same material. They are big cast. The ratio of the solidification time of the cube to the same of the sphere is

A. (4π/6)³ × (r/l)⁶

B. (4π/6) × (r/l)²

C. (4π/6)² × (r/l)³

D. (4π/6)² × (r/l)⁴