**Core Concept**
Iron replacement therapy is essential to replenish iron stores in patients with iron deficiency anemia. Elemental iron is the form of iron that is directly absorbed by the body, and its adequate dosage is crucial for effective treatment.

**Why the Correct Answer is Right**
The recommended daily allowance (RDA) for elemental iron varies based on factors such as age, sex, and pregnancy status. For adults, the RDA for elemental iron is approximately 8 milligrams per day for men and 18 milligrams per day for non-pregnant women. However, for iron replacement therapy, higher doses are often required to rapidly replenish iron stores. A common dosage range for elemental iron is 150-200 milligrams per day, taken in divided doses with meals to enhance absorption.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely too low for effective iron replacement therapy.
* **Option B:** This option is too high and may cause gastrointestinal side effects.
* **Option C:** This option is incorrect because it does not specify the form of iron (elemental, ferrous sulfate, etc.).

**Clinical Pearl / High-Yield Fact**
When prescribing iron replacement therapy, it is essential to consider the type of iron supplement, as different forms have varying absorption rates. For example, ferrous sulfate has a higher bioavailability compared to ferrous gluconate.

**Correct Answer: C. 180 milligrams.**