Final answer:
The Nissen fundoplication procedure is done to correct a hiatal hernia by wrapping the top of the stomach around the lower part of the esophagus to strengthen the valve between them and prevent acid reflux.
Step-by-step explanation:
The correct answer for the Nissen fundoplication procedure is a. Hiatal hernia. A Hiatal hernia occurs when the upper part of the stomach protrudes through the diaphragm into the chest cavity. During a Nissen fundoplication procedure, the top of the stomach is wrapped around the lower part of the esophagus to strengthen the valve between the esophagus and the stomach. This helps prevent acid reflux and reduces symptoms such as heartburn.