Whole grains, like oats, barley, and wheat, are good sources of the b-complex vitamins. these foods are also considered very good sources of energy. why would whole grains be good sources of energy? a. they are rich in complex carbohydrates which provide energy, and their b-complex vitamins are important for transporting these carbohydrates to cells that need energy. b. they are rich in fats, which can only be transported to energy-producing cells with the of b-complex vitamins. c. they are rich in fats, which are broken down and stored in the body through processes that require b-complex vitamins. d. they are rich in complex carbohydrates which can be broken down for energy, and their b-complex vitamins are involved in metabolic processes that release this energy.