**Core Concept**
Rigler's Sign is a radiological finding seen in conditions where there is an air-fluid level within a hollow viscus, indicating a perforation of the viscus. This sign is characterized by the presence of air on both sides of a fluid level, creating a "double bubble" appearance.

**Why the Correct Answer is Right**
Rigler's Sign is seen in cases of hollow viscus perforation, where air leaks from the gut into the surrounding tissues or peritoneal cavity. The air then mixes with the fluid (blood, pus, or bile) within the viscus, creating an air-fluid level. In conditions like intestinal obstruction, the air-fluid level may be seen on a plain abdominal radiograph. The presence of air on both sides of the fluid level is a key feature of Rigler's Sign.

**Why Each Wrong Option is Incorrect**
**Option A:** Not applicable - Rigler's Sign is not associated with this condition.
**Option B:** Incorrect - Rigler's Sign is not a feature of this condition; it is associated with hollow viscus perforation, not solid organ injury.
**Option C:** Incorrect - Rigler's Sign is not seen in this condition; it is associated with air-fluid levels within a hollow viscus, not with a solid mass.

**Clinical Pearl / High-Yield Fact**
Rigler's Sign is an important radiological finding that can indicate a perforated hollow viscus, which is a surgical emergency. Remember to look for air on both sides of the fluid level to confirm the presence of Rigler's Sign.

**Correct Answer: D.**