The ratio of the weights of a body on Earth's surface to that on the surface of a planet is 9:4. The mass of the planet is $$\frac{1}{9}$$th of that of the Earth. If R is the radius of the Earth, what is the radius of the planet? (Take the planets to have the same mass density)

A

$$\frac{R}{4}$$

B

$$\frac{R}{2}$$

C

$$\frac{R}{3}$$

D

$$\frac{R}{9}$$