The volume of a right circular cone. whose radius of the base is one-third of its altitude. and the volume of a hemisphere are equal. The ratio of the radii of the cone and the hemisphere is:

A

$$\sqrt[3]{3} : \sqrt[3]{2}$$

B

2 : 3

C

$$\sqrt[3]{2} : 1$$

D

$$\sqrt[3]{2} : \sqrt[3]{3}$$