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
Which of the following is not compatible with a diagnosis of juvenile myelomonocytic leukemia? 
Select and explain. 
A. Peripheral blood monocytosis, more than 1 x 107L, B. Increased Hemoglobin F levels for age, C. Presence of bcr/abl fusion gene, D. GM - CSF hypersensitivity of myeloid progenitors in vitro
C: Presence of bcr/abl fusion gene
Answer: C: Presence of bcr/abl fusion gene 
Explanation: . Presence of bcr/abl fusion gene