A spherical balloonis filled with $$3536 \pi$$ cubic meters of helium gas. If a leak in the balloon causes the gas to escape at the rate of $$70 \pi$$ cubic meters per minute, then the rate (in meters per minute) at which the radius of the balloon decreases 50 minutes after the leakage began is

A

$$\frac{1}{9}$$

B

$$\frac{1}{2}$$

C

$$\frac{2}{9}$$

D

$$\frac{35}{18}$$