**Core Concept**
Chronic Myeloid Leukemia (CML) is a type of cancer that affects the white blood cells and is characterized by the uncontrolled growth of myeloid cells in the bone marrow. The disease is associated with a specific chromosomal abnormality known as the Philadelphia chromosome, resulting from a translocation between chromosomes 9 and 22. The treatment of CML involves targeting the molecular abnormality responsible for the disease.

**Why the Correct Answer is Right**
The drug of choice in CML is Imatinib, a tyrosine kinase inhibitor that specifically targets the BCR-ABL tyrosine kinase, which is the result of the Philadelphia chromosome translocation. Imatinib works by binding to the ATP-binding site of the BCR-ABL tyrosine kinase, thereby inhibiting its activity and preventing the proliferation of CML cells. This results in the reduction of white blood cell count and improvement in symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** Hydroxyurea is a chemotherapy agent that can be used to reduce white blood cell count in CML, but it is not the drug of choice due to its lack of specificity and potential for toxicity. **Option B:** Interferon-alpha has been used in the treatment of CML, but it is not as effective as Imatinib and is associated with more side effects. **Option C:** Ara-C (Cytarabine) is a chemotherapy agent that is used in the treatment of acute leukemias, but it is not effective in CML.

**Clinical Pearl / High-Yield Fact**
Imatinib was the first targeted therapy to be approved for the treatment of CML and has revolutionized the management of this disease. Its approval has led to significant improvements in patient outcomes and survival rates.

**Correct Answer:** C. Imatinib.