This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
The first-line drug therapy in chronic myeloid leukemia is - 
Select and explain. 
A. Hydroxycarbamide, B. Alpha-interferon, C. Busulphan, D. Imatinib
D: Imatinib
Answer: D: Imatinib 
Explanation: None