**Core Concept**
Parenteral iron therapy involves administering iron intravenously or intramuscularly to treat iron deficiency anemia. This method is typically reserved for patients who cannot tolerate oral iron supplementation or have severe iron deficiency. The choice of parenteral iron preparation is critical to ensure safe and effective treatment.

**Why the Correct Answer is Right**
Ferumoxytol is an intravenous iron replacement product used for the treatment of iron deficiency anemia in adult patients with chronic kidney disease (CKD). It is a superparamagnetic iron oxide complex that is absorbed by the reticuloendothelial system, releasing iron for erythropoiesis. Ferumoxytol is administered as a single dose or divided doses over a few days, depending on the patient's iron needs.

**Why Each Wrong Option is Incorrect**
**Option A:** Iron dextran is a form of parenteral iron, but it is not typically used for iron deficiency anemia in patients with CKD. It is more commonly used for patients with iron deficiency anemia not related to CKD.
**Option B:** Iron sucrose is another form of parenteral iron, but it is not the preferred choice for patients with CKD. It can cause more frequent adverse reactions compared to ferumoxytol.
**Option C:** Ferric gluconate is a parenteral iron preparation, but it is not used for patients with CKD. It is more commonly used for patients with iron deficiency anemia not related to CKD.

**Clinical Pearl / High-Yield Fact**
Ferumoxytol is a high-osmolar iron preparation, which may increase the risk of anaphylaxis. Therefore, it is essential to monitor patients closely during administration and have resuscitation equipment available.

**Correct Answer:** C.