Energy may be defined as A. Power of doing work B. Capacity of doing work C. Rate of doing work D. All the above

The correct answer is D. All of the above.

Energy is the ability to do work. It can be stored in many different forms, such as heat, light, electricity, and chemical energy. Energy can be converted from one form to another, but it cannot be created or destroyed.

Power is the rate at which energy is used or transferred. It is measured in watts, which are joules per second.

Work is the transfer of energy from one object to another by means of a force. It is measured in joules.

Therefore, energy can be defined as the power of doing work, the capacity of doing work, or the rate of doing work.