Answer:d.catabolic
Step-by-step explanation:
Catabolism helps break complex molecules into smaller molecules during metabolism whereas anabolism builds complex molecules from simple molecules. Energy get released when the complex molecules get broken down during catabolism, this energy get restored in adenosine triphosphate.
When animals require energy they will eat food which get stored as glucose ,glucose which is derived from carbohydrates by certain enzymes during primary function of the catabolism. The catabolic pathway glycolysis is responsible for further breaking down this glucose into pyruvate molecules.