The correct answer is a) anabolism.
Anabolism refers to the metabolic pathways that construct molecules from smaller units. These processes require energy, often in the form of ATP. For example, protein synthesis, where amino acids are linked together to form proteins, is an anabolic process. In contrast, catabolism involves breaking down larger molecules into smaller ones, releasing energy. Understanding these two processes is crucial for grasping how organisms grow, repair tissues, and store energy.