Final answer:
Cricoid pressure is applied to occlude the esophagus and prevent regurgitation during intubation. Hence, option D is correct.
Step-by-step explanation:
The purpose of applying cricoid pressure is to occlude the esophagus. Cricoid pressure, also known as Sellick's maneuver, is a technique used during intubation to prevent regurgitation of gastric contents into the patient's airway. By applying pressure on the cricoid cartilage located in the neck, the esophagus is compressed and blocked, reducing the risk of aspiration and helping to maintain the airway.