The answer to this is B. There are a lot of people who feel that their lack of energy is the reason why they are unable to do the tasks that they have to do. The various units that are used to describe energy will also show how much energy is available or is being used.
Everything that can be found here on earth has a certain amount of energy. Some come with potential energy, but there are also some that come with kinetic energy. The more energy that something has, the more that it can do. Even colors have different amounts of energy.