**Core Concept**
Spiral muscles are a type of smooth muscle found in the gastrointestinal tract, specifically in the stomach and intestine. They play a crucial role in the peristaltic movement of food through the digestive system.

**Why the Correct Answer is Right**
Spiral muscles are characterized by their unique arrangement and function. They are not found in the gallbladder, which is a hollow organ that stores bile. The correct answer is likely related to this anatomical fact. Spiral muscles are involved in the contraction and relaxation of the stomach and intestine, propelling food through the digestive system.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because spiral muscles are indeed found in the stomach, which is a key location for peristalsis.
**Option B:** Incorrect because spiral muscles are not found in the gallbladder, which is a distinct organ with a different function.
**Option C:** Incorrect because spiral muscles are not found in the small intestine, which is also involved in peristalsis but has a different type of muscle arrangement.
**Option D:** Incorrect because spiral muscles are not found in the large intestine, which has a different type of muscle arrangement.

**Clinical Pearl / High-Yield Fact**
Spiral muscles are responsible for the peristaltic waves that propel food through the digestive system, and their dysfunction can lead to conditions such as gastroparesis or intestinal obstruction.

**Correct Answer: B. Gallbladder**