The power of a Porter governor is equal to

A. $$\left( {\frac{{{{\text{c}}^{\text{2}}}}}{{{\text{1}} + {\text{2c}}}}} \right)\left( {{\text{m}} + {\text{M}}} \right){\text{g}}{\text{.h}}$$

B. $$\left( {\frac{{{\text{2}}{{\text{c}}^{\text{2}}}}}{{{\text{1}} + {\text{2c}}}}} \right)\left( {{\text{m}} + {\text{M}}} \right){\text{g}}{\text{.h}}$$

C. $$\left( {\frac{{{\text{3}}{{\text{c}}^{\text{2}}}}}{{{\text{1}} + {\text{2c}}}}} \right)\left( {{\text{m}} + {\text{M}}} \right){\text{g}}{\text{.h}}$$

D. $$\left( {\frac{{{\text{4}}{{\text{c}}^{\text{2}}}}}{{{\text{1}} + {\text{2c}}}}} \right)\left( {{\text{m}} + {\text{M}}} \right){\text{g}}{\text{.h}}$$

Answer: Option D