Final answer:
Pyloric Stenosis is the narrowing of the lower end of the duodenum and can cause regular vomiting in infants due to obstruction of food flow. The correct option is a).
Step-by-step explanation:
The diagnostic term Pyloric Stenosis refers to the narrowing of the lower end of the duodenum, which is the first part of the small intestine directly connected to the stomach.
Pyloric Stenosis can lead to regular vomiting in infants because the narrowed passage can obstruct the flow of food from the stomach into the duodenum, leading to a build-up and eventual regurgitation.
The pyloric sphincter is a muscular valve that separates the stomach from the duodenum and regulates the passage of chyme from the stomach to the small intestine. Option a) is the correct one.