The correct answer is C. calories.
A calorie is a unit of energy. It is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. The energy of food is measured in calories because food is a source of energy for the body. When we eat food, our bodies break it down into smaller molecules that can be used for energy. These molecules are then burned in the body, releasing heat energy. This heat energy is used to power our cells and keep our bodies functioning.
The other options are incorrect. Kelvin is a unit of temperature, not energy. Bushel is a unit of volume, not energy. None of the above is the correct answer because it is not one of the options listed.