**Core Concept**
The Sengstaken-Blakemore tube is used to control bleeding from esophageal varices, and its balloon tamponade can cause pressure necrosis of the esophagus if left inflated for too long. **Esophageal pressure necrosis** is a serious complication that can occur due to prolonged compression of the esophageal wall.

**Why the Correct Answer is Right**
The correct answer is based on the recommendation to temporarily deflate the balloon of the Sengstaken-Blakemore tube after a certain period to prevent **ischemic injury** to the esophagus. This allows for intermittent relief of pressure on the esophageal wall, reducing the risk of **necrosis**.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because deflating too soon may not prevent necrosis.
**Option B:** This option is also incorrect as it may still cause necrosis.
**Option D:** This option is incorrect because it exceeds the recommended time frame.

**Clinical Pearl / High-Yield Fact**
It is crucial to monitor patients with a Sengstaken-Blakemore tube closely and follow the recommended protocol for balloon deflation to avoid complications.

**Correct Answer:** C. 12 hours