Which of the following is not an example of energy transfer?

A book resting on a table does not involve energy transfer because there is no movement or change in the book's position or state. Energy transfer occurs when there is a change in the form or location of energy. In the case of the other options, energy is being transformed or transferred. For example, in a candle burning, chemical energy is being converted into heat and light energy. In a person walking upstairs, mechanical energy is being transferred from the person's muscles to their movement. In a radio playing, electrical energy is being converted into sound energy.