**Core Concept**
Iron overload is a serious complication of parenteral iron therapy. The safe dose of intravenous iron is crucial to avoid adverse effects, including cardiac and liver toxicity.

**Why the Correct Answer is Right**
The recommended dose of iron gluconate for intravenous administration is 25 mg or 50 mg per 250 mL of solution. This is equivalent to 100 mg or 200 mg of elemental iron per 250 mL. The dose is limited by the risk of cardiac arrhythmias and hypotension. The maximum dose should not exceed 1000 mg (2000 mg of iron gluconate) in 250 mL of solution administered over 1 hour.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the dose or the rate of administration.
**Option B:** This option is incorrect because it exceeds the recommended maximum dose.
**Option C:** This option is incorrect because it is below the recommended dose and may not be effective for patients with iron deficiency.

**Clinical Pearl / High-Yield Fact**
When administering intravenous iron, it is essential to use a central line and to monitor the patient's cardiac rhythm and blood pressure closely. A rapid infusion of iron can lead to cardiac arrhythmias and hypotension.

**Correct Answer:** D.