Which of the following equations for the efficiency of a machine is correct?

• A.Efficiency = \(\frac{\text{Velocity Ratio}}{\text{Mechanical Advantage}}\) x 100%
• B.Efficiency = \(\frac{input}{output}\) x 100%
• C.Efficiency = \(\frac{\text{load distance}}{\text{effort distance}}\) x 100%
• D.Efficiency = \(\frac{\text{Mechanical Advantage}}{\text{Velocity Ratio}}\) x 100%