**Core Concept**
During endoscopy, identifying active bleeding from varices is crucial for timely management and intervention. The presence of certain signs can indicate active bleeding from varices, which can be life-threatening if not addressed promptly.

**Why the Correct Answer is Right**
Active bleeding from varices during endoscopy is often identified by the presence of blood in the stomach or intestine, which can be visualized as a red or black discoloration. The presence of **esophageal variceal bleeding (EVB)** is a medical emergency that requires immediate intervention. The correct indicators of active bleeding from varices include the presence of **red wale marks**, which are linear, red streaks on the varices, and **hemorrage**, which is the presence of blood in the stomach or intestine.

**Why Each Wrong Option is Incorrect**
**Option A:** **Ascites** is a sign of portal hypertension, which can lead to the development of varices, but it is not an indicator of active bleeding from varices.
**Option B:** **Hepatomegaly** is a sign of liver disease, which can lead to portal hypertension and variceal bleeding, but it is not a direct indicator of active bleeding.
**Option C:** **Melena** is a sign of upper gastrointestinal bleeding, which can be caused by variceal bleeding, but it is not specific to variceal bleeding.

**Clinical Pearl / High-Yield Fact**
Red wale marks on esophageal varices during endoscopy are a high-yield sign of active bleeding from varices. Remember the acronym "RED" to identify active bleeding from varices: **R**ed wale marks, **E**xternal bleeding, and **D**ecreased blood pressure.

**Correct Answer: C. Melena**