The correct answer is B. Losses.
Efficiency is a measure of how much of the input energy is converted into useful output energy. A machine with high efficiency is one that converts most of its input energy into useful output energy.
Losses are any energy that is not converted into useful output energy. They can occur in many different ways, such as through heat, friction, or sound.
The higher the losses, the lower the efficiency. Therefore, if the efficiency of a machine is to be high, the losses must be low.
A. Input power is the amount of energy that is supplied to the machine. It is not affected by losses, so it does not affect the efficiency.
C. True component of power is the amount of power that is actually used by the machine. It is equal to the input power minus the losses. Therefore, the true component of power is higher when the losses are lower.
D. kWh consumed is the amount of energy that is used by the machine over time. It is equal to the input power multiplied by the time that the machine is in use. Therefore, kWh consumed is higher when the input power is higher or when the machine is in use for a longer time.