Which ratio defines the height of a porter governor to that of the watt governor for equal arm and link lengths, where m is the massof the ball and M is the massof the sleeve?

A

$$\frac{m}{M + m}$$

B

$$\frac{M}{M + m}$$

C

$$\frac{M + m}{m}$$

D

$$\frac{M + m}{M}$$