Answer: Option D
Let their radii be R and r
Then,
$$\eqalign{
& \frac{{4\pi {R^2}}}{{4\pi {r^2}}} = \frac{4}{{25}} \cr
& \Rightarrow {\left( {\frac{R}{r}} \right)^2} = {\left( {\frac{2}{5}} \right)^2} \cr
& \Rightarrow \frac{R}{r} = \frac{2}{5} \cr} $$
∴ Ratio of volumes :
$$\eqalign{
& = \frac{{\frac{4}{3}\pi {R^3}}}{{\frac{4}{3}\pi {r^3}}} \cr
& = {\left( {\frac{R}{r}} \right)^3} \cr
& = {\left( {\frac{2}{5}} \right)^3} \cr
& = \frac{8}{{125}} \cr
& = 8:125 \cr} $$