This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Acute Myelogenous Leukemia, Subject name: Pathology
Which of the following is not compatible with a diagnosis of chronic myelomonocytic leukemia? 
Select and explain. 
A. Peripheral blood monocytosis more than 1 x 109/L, B. Absence of Philadelphia chromosome, C. More than 20% blasts in blood or bone marrow, D. Myelodysplasia
C: More than 20% blasts in blood or bone marrow
Answer: C: More than 20% blasts in blood or bone marrow 
Explanation: WHO (2017) Diagnostic criteria of CMML: Persistent peripheral blood monocytosis (>= 1 x 109/L) with monocytes accounting for >= 10% of the leukocytes WHO criteria for BCR-ABL1--positive chronic myeloid leukaemia, primary myelofibrosis, polycythaemia vera and essential thrombocythaemia are not met No rearrangement of PDGFRA, PDGFRB or FGFR1 and no PCM1-JAK2 Blasts (incl. promonocytes) constitute < 20% of the cells in the peripheral blood and bone marrow Dysplasia involving >= 1 myeloid lineages orIf myelodysplasia is absent or minimal, criteria 1-4 are met and:- an acquired, clonal cytogenetic or molecular genetic abnormality is present in haematopoietic cells, or- the monocytosis has persisted for >=3 months and all other causes of monocytosis (e.g. malignancy, infection, and inflammation) have been excluded