Concept:Growth depends on the balance between building up and breaking down body materials.Explanation:Anabolism involves building larger, complex molecules from smaller ones. This increases cell size and number.Catabolism involves breaking down complex molecules to release energy. This reduces body materials.For growth to occur, the rate of tissue building must be higher than the rate of tissue breakdown.Thus, the rate of anabolism must exceed that of catabolism.Answer:A. anabolism must exceed that of catabolism.