Final answer:
Option (C), Trypsin is the enzyme that breaks down polypeptides into shorter peptides and amino acids, aiding in protein digestion.
Step-by-step explanation:
The enzyme that aids in digesting polypeptides into shorter peptides and amino acids is trypsin. Trypsin, along with elastase, and chymotrypsin, are produced by the pancreas and released into the duodenum. They act on the chyme to break down proteins into smaller peptides.
Additional enzymes like carboxypeptidase, dipeptidase, and aminopeptidase, which are referred to as peptidases, continue the breakdown of peptides into free amino acids that can be absorbed into the bloodstream.