Answer: D. They act to break down the protective barriers around the egg, allowing the sperm.
Step-by-step explanation:
Acrosin and other protease enzymes functions by the catalyzing the proteolysis, that is the breakdown of proteins into small polypeptides by cleaving the peptide bonds within the proteins by the process of hydrolysis.
The acrosine and other protease enzymes are released by the acrosome cap of the spermatozoa. This process facilitates the enzymatic digestion of zona pellucida layer of the egg. This helps in the penetration of egg by the sperm.