**Core Concept:**
Von-Rosen's sign is a clinical sign used to differentiate between acute appendicitis and acute pancreatitis. It involves pressing on the epigastrium (upper abdomen) and observing the patient's response. A positive sign suggests acute pancreatitis due to the protective mechanism of the diaphragm preventing direct pressure on the inflamed gland.

**Why the Correct Answer is Right:**
Von-Rosen's sign is positive when the patient experiences spontaneous pain or cramping in response to epigastric pressure, indicating inflammation or trauma to the pancreas. In acute appendicitis, there is no such response as the appendix is located in the right lower quadrant, separated from the epigastrium by the diaphragm.

**Why Each Wrong Option is Incorrect:**
A. Option A is incorrect because pressing on the epigastrium in acute appendicitis may cause pain, but the protective diaphragm prevents direct pressure on the inflamed appendix.
B. Option B is incorrect because acute pancreatitis can cause pain in the epigastrium, making this option less specific compared to the correct answer.
C. Option C is incorrect because pressing on the epigastrium will not cause spontaneous pain in healthy individuals, making this option less sensitive than the correct answer.
D. Option D is incorrect because the diaphragm protects the inflamed pancreas in acute pancreatitis, preventing direct pressure on the gland.

**Clinical Pearl:**
Von-Rosen's sign is a valuable clinical test to consider when suspecting acute pancreatitis, particularly when combined with other clinical findings like epigastric pain radiating to the back and a positive Murphy's sign (inspiratory shortness of breath during deep breathing). However, this test should be interpreted in conjunction with the patient's clinical presentation and overall examination to avoid over-reliance on a single sign and to differentiate it from other abdominal conditions.