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: Pathology
A patient has the following findings -splenomegaly,low RBC count, normal WBC and platelet count and peripheral blood smear shows target cells. Repeated BM aspiration is unsuccessful. The probable diagnosis is - 
Select and explain. 
A. Thalassemia, B. Chronic myeloid leukemia, C. Iron deficiency anaemia, D. Myelofibrosis
D: Myelofibrosis
Answer: D: Myelofibrosis 
Explanation: None