A spherical balloon is filled with $4500\pi$ cubic meters of helium gas. If a leak in the balloon causes the gas to escape at the rate of $72\pi$ cubic meters per minute, then the rate (in meters per minute) at which the radius of the balloon decreases $49$ minutes after the leakage began is:

1. A
   $\frac{9}{7}$
2. B
   $\frac{7}{9}$
3. C
   $\frac{2}{9}$
4. D
   $\frac{9}{2}$