**Core Concept**
Griesinger's sign is a clinical sign associated with an intra-abdominal condition that presents with a characteristic physical examination finding. It is a significant indicator of a specific condition that requires prompt medical attention.

**Why the Correct Answer is Right**
Griesinger's sign is seen in a case of **Pyloric Stenosis**. When a patient with pyloric stenosis is fed, the stomach becomes distended due to the obstruction caused by the hypertrophied pylorus. This distension leads to the visible **Palpable gastric air-fluid level** on the left side of the abdomen, which is Griesinger's sign. The hypertrophied pylorus is responsible for the obstruction, and the resulting distension of the stomach is the mechanism behind Griesinger's sign.

**Why Each Wrong Option is Incorrect**
**Option A:** Griesinger's sign is not seen in **Gastrointestinal Stromal Tumors (GISTs)**, as GISTs present with different clinical features such as abdominal pain, weight loss, and gastrointestinal bleeding.
**Option B:** Griesinger's sign is not associated with **Inflammatory Bowel Disease (IBD)**, as IBD presents with symptoms such as diarrhea, abdominal pain, and weight loss, and does not typically cause a palpable gastric air-fluid level.
**Option C:** Griesinger's sign is not a characteristic finding in **Gastric Cancer**, as gastric cancer presents with symptoms such as weight loss, abdominal pain, and gastrointestinal bleeding, and does not typically cause a palpable gastric air-fluid level.

**Clinical Pearl / High-Yield Fact**
Remember that Griesinger's sign is a specific physical examination finding associated with pyloric stenosis, and it is characterized by a palpable gastric air-fluid level on the left side of the abdomen. This sign is a key indicator of the condition and should prompt further investigation.

**Correct Answer: C. Pyloric Stenosis**