## **Core Concept**
Schatzki's Ring is a type of esophageal ring that is a narrow, membranous ring of tissue that can cause dysphagia. It is located at the junction of the esophagus and the stomach.

## **Why the Correct Answer is Right**
The correct answer, **C. Gastroesophageal junction**, is right because Schatzki's Ring is specifically found at the gastroesophageal junction (GEJ), which is the area where the esophagus transitions into the stomach. This ring is composed of mucosa and submucosa and can lead to difficulty swallowing (dysphagia) due to its narrow diameter.

## **Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Schatzki's Ring is not typically associated with the upper part of the esophagus.
* **Option B:** This option is incorrect as it refers to a different location and does not accurately describe the site where Schatzki's Ring is found.
* **Option D:** This option is incorrect because Schatzki's Ring is specifically located at the gastroesophageal junction, not at the lower part of the trachea or any other site.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that Schatzki's Ring is a common cause of intermittent dysphagia, particularly for solid foods. It is often associated with an increased risk of food impaction. The diagnosis can be made through barium swallow studies or endoscopy.

## **Correct Answer:** C. Gastroesophageal junction.