Final answer:
Omeprazole is the medication that inhibits gastric acid secretion and is used to treat peptic ulcer disease.
Step-by-step explanation:
The medication that inhibits gastric acid secretion is Omeprazole. Omeprazole belongs to a class of medications called proton pump inhibitors, which work by decreasing the amount of acid produced in the stomach. It is commonly used to treat peptic ulcer disease and other conditions where excess stomach acid is a problem.