**Core Concept**
Proton pump inhibitors (PPIs) are a class of drugs used to reduce gastric acid secretion by irreversibly inhibiting the H+/K+ ATPase enzyme, also known as the gastric proton pump. This is crucial in managing conditions like peptic ulcer disease, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome.

**Why the Correct Answer is Right**
Pantoprazole is a PPI that has a unique property among its class: it can be administered intravenously (IV). This is because pantoprazole has a high solubility in water, allowing it to be dissolved in IV fluids. The IV formulation of pantoprazole is particularly useful in situations where oral administration is not feasible, such as in critically ill patients or those with severe gastrointestinal bleeding. The mechanism of action of pantoprazole involves covalently binding to the sulfhydryl group of cysteine residues on the gastric proton pump, thereby inhibiting its activity.

**Why Each Wrong Option is Incorrect**
**Option A:** Omeprazole is available in oral and intravenous formulations, but its IV formulation has largely been discontinued due to concerns about its stability and potency.
**Option B:** Rabeprazole is not approved for IV administration, and its pharmacokinetic properties make it less suitable for this route.
**Option D:** Fomeprazole is not a recognized proton pump inhibitor; it is possible that the question intended to refer to omeprazole (A) or another PPI.

**Clinical Pearl / High-Yield Fact**
When choosing a PPI for IV administration, pantoprazole is a reliable option due to its high solubility and stability in IV fluids. However, it is essential to be aware of the potential for IV formulations of PPIs to be discontinued or withdrawn from the market.

**✓ Correct Answer: C. Pantoprazole**