Match List I with List II and select the correct answer using the codes given below the Lists: List I List II (Substance) (Physiological role) I. Ptyalin A) Converts angioten-sinogen in blood into angiotensin II. Pepsin B) Digests starch III. Renin C) Digests proteins IV. Oxytocin D) Hydrolyses fats E) Induces contraction of smooth muscles

The correct answer is A based on the specific physiological roles of the listed substances. Ptyalin, also known as salivary amylase, is an enzyme in saliva that begins the process of breaking down starch into simpler sugars. Pepsin is a digestive enzyme found in the stomach that breaks down proteins into smaller peptides. Renin is an enzyme secreted by the kidneys that plays a key role in the renin-angiotensin system by converting angiotensinogen into angiotensin, which helps regulate blood pressure. Oxytocin is a hormone that acts as a neurotransmitter and is well known for inducing the contraction of smooth muscles, particularly during childbirth and breastfeeding. Therefore, the correct mapping is Ptyalin to Digests starch, Pepsin to Digests proteins, Renin to Angiotensin conversion, and Oxytocin to Muscle contraction. Note that Option D in List II, Hydrolyses fats, refers to Lipase and is not a match for any substance in List I.