**Core Concept**
Beta-thalassemia major is a genetic disorder characterized by the production of abnormal hemoglobin proteins, leading to severe microcytic anemia. Patients with this condition often require frequent blood transfusions to alleviate symptoms and prevent complications such as skeletal deformities and developmental delays. However, regular blood transfusions can lead to iron overload due to the accumulation of iron from the transfused red blood cells.

**Why the Correct Answer is Right**
Desferrioxamine is an iron-chelating agent that binds to excess iron in the body, preventing its accumulation and reducing the risk of iron overload. This is particularly important in patients with beta-thalassemia major who require frequent blood transfusions. By chelating iron, desferrioxamine helps to prevent complications such as heart failure, liver disease, and diabetes that can arise from iron overload. The subcutaneous administration of desferrioxamine is the most common route of administration.

**Why Each Wrong Option is Incorrect**
**Option A:** Oral calcium supplements are not indicated in the treatment of patients requiring frequent blood transfusions. While calcium supplements may be necessary to prevent osteoporosis in patients with beta-thalassemia major, they do not address the issue of iron overload.

**Option B:** Fresh frozen plasma (FFP) is not indicated in the treatment of patients requiring frequent blood transfusions. FFP is used to replace clotting factors in patients with bleeding disorders, but it does not have a role in the management of iron overload.

**Option D:** Penicillamine is a chelating agent used to treat heavy metal poisoning, such as lead or mercury poisoning, but it is not used to treat iron overload. Penicillamine can actually increase the risk of iron overload in patients with beta-thalassemia major.

**Clinical Pearl / High-Yield Fact**
It is essential to monitor patients with beta-thalassemia major for signs of iron overload, including elevated serum ferritin levels, and to initiate iron chelation therapy with desferrioxamine as soon as possible to prevent long-term complications.

**Correct Answer:**
✓ Correct Answer: C. desferrioxamine