Final answer:
Caseinase is an extracellular protease enzyme that breaks down casein, a milk protein.
Step-by-step explanation:
Caseinase is an extracellular protease enzyme that breaks down casein, a milk protein. Therefore, the correct answer is option C. Proteases are enzymes that break down proteins into smaller fragments or amino acids. Caseinase specifically acts on casein, which is found in milk. Example of proteases include pepsin and trypsin, which are involved in the digestion of proteins in the stomach and small intestine.