A 45 yrs old female patient presents with symptoms of easy bruisability and frequent headaches.Physical examination show a moderate splenomegaly.Blood counts shows a normal leucocyte count and a platelet count of 1000 x 103/cu mm.The leucocyte alkaline phosphatase score is normal.Which one of the following is the drug of choice for the treatment of this patient?

• A. Hydroxyurea
• B. Radioactive phosphorus
• C. Anagrelide
• D. Interferon alpha