A solid is in the shape of a cone fitted on a hemisphere both with radii 2 cm and height of cone being equal to its radius. What is the volume of this solid?

A

$$ 2\pi cm^3 $$

B

$$ 4\pi cm^3 $$

C

$$ 6\pi cm^3 $$

D

$$ 8\pi cm^3 $$