Correct Answer: DThe principal diagnosis is defined as the condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care. Although the patient presented with severe abdominal pain, elevated temperature, and nausea, which led to consideration of cholecystitis, the final diagnosis was acute and chronic pancreatitis secondary to alcoholism. Therefore, the principal diagnosis is acute pancreatitis, as it was the condition identified after further study that necessitated the patient's admission.