**Core Concept**
Gastrointestinal enteritis necroticans, also known as pigbel disease, is a severe and often fatal form of enteritis caused by a bacterial infection. The condition is characterized by necrosis of the intestinal mucosa, leading to severe abdominal pain, diarrhea, and potentially life-threatening complications.

**Why the Correct Answer is Right**
The correct answer is Clostridium perfringens type C. This bacterium produces a toxin that causes the intestinal mucosa to become necrotic, leading to the characteristic symptoms of the disease. Clostridium perfringens type C is a toxin-producing strain that is typically found in the gastrointestinal tracts of animals, particularly pigs, and is transmitted to humans through contaminated food or water.

**Why Each Wrong Option is Incorrect**
* **Option A:** Staphylococcus aureus is a common cause of food poisoning, but it is not associated with enteritis necroticans.
* **Option B:** Escherichia coli can cause a range of gastrointestinal infections, but it is not the primary cause of enteritis necroticans.
* **Option D:** Clostridium difficile is a common cause of antibiotic-associated diarrhea, but it is not associated with enteritis necroticans.

**Clinical Pearl / High-Yield Fact**
Clostridium perfringens type C is a highly virulent strain that can cause severe gastrointestinal disease, particularly in individuals who consume contaminated meat or have a compromised immune system.

**Correct Answer: C. Clostridium perfringens type C.**