The specific surface of spherical particles is given by (where D and $$\rho $$ are diameter and density of particle).

A. $$\frac{6}{{{\text{D}}.\rho }}$$

B. $$\frac{2}{{{\text{D}}.\rho }}$$

C. $$\frac{4}{{{\text{D}}.\rho }}$$

D. $$\frac{{12}}{{{\text{D}}.\rho }}$$

Answer: Option A