The appropriate answer is A. carbohydrates. Carbohydrate is an energy rich substance found in foods such as vegetables, cereal grains and breads. Carbohydrates can be easily broken down to glucose, which is the basic unit or molecule used in the process of cellular respiration.
Foods from animals such as milk, eggs and meat are a rich source of protein. Vitamins are present in all food groups and these are essential in regulating growth and normal body functioning.