The correct match between List I (Substance) and List II (Physiological role) is as follows:

I. Ptyalin - (B) Digests starch: Ptyalin, also known as salivary amylase, is an enzyme present in saliva that initiates the digestion of starches and complex carbohydrates by breaking them down into simpler sugars.

II. Pepsin - (C) Digests proteins: Pepsin is an enzyme produced in the stomach that plays a key role in the digestion of proteins. It breaks down proteins into smaller peptide fragments.

III. Renin - (A) Converts angiotensinogen in blood into angiotensin: Renin is an enzyme produced by special cells in the kidneys. Its primary role is to convert angiotensinogen, a protein released by the liver, into angiotensin. Angiotensin plays a crucial role in regulating blood pressure and fluid balance.

IV. Oxytocin - (E) Induces contraction of smooth muscles: Oxytocin is a hormone produced by the hypothalamus and released by the posterior pituitary gland. Its primary physiological role is to stimulate uterine contractions during labor and delivery. It also plays a role in the ejection of milk during breastfeeding and can have effects on social bonding and behavior.

Therefore, the correct match between List I and List II is:

I-B, II-C, III-A, IV-E.