To solve this problem, we need to identify the components of gastric juice in infants. Let's analyze the options:$\newline \bullet$Option 1: Maltase, pepsinogen, rennin$\newline$ - Maltase is an enzyme that breaks down maltose into glucose, but it is not typically found in gastric juice.$\newline$ - Pepsinogen is an inactive precursor of pepsin, an enzyme that digests proteins, and is found in gastric juice.$\newline$ - Rennin is an enzyme that helps in the digestion of milk proteins and is present in the gastric juice of infants.$\newline$ - Therefore, this option is incorrect because maltase is not part of gastric juice.$\newline \bullet$Option 2: Nuclease, pepsinogen, lipase$\newline$ - Nuclease is an enzyme that digests nucleic acids and is not typically found in gastric juice.$\newline$ - Pepsinogen and lipase are present in gastric juice, but the presence of nuclease makes this option incorrect.$\newline \bullet$Option 3: Pepsinogen, lipase, rennin$\newline$ - Pepsinogen is present in gastric juice and is converted to pepsin to digest proteins.$\newline$ - Lipase is an enzyme that digests fats and is present in the gastric juice of infants.$\newline$ - Rennin is also present in the gastric juice of infants to help digest milk proteins.$\newline$ - All components listed are correct, making this the correct option.$\newline \bullet$Option 4: Amylase, rennin, pepsinogen$\newline$ - Amylase is an enzyme that digests carbohydrates and is not typically found in gastric juice.$\newline$ - Rennin and pepsinogen are present, but the presence of amylase makes this option incorrect.$\newline$Therefore, the correct answer is Option 3: Pepsinogen, lipase, rennin.