This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Myelogenous Leukemia, Subject name: Pathology
Leucocyte alkaline phosphatase (LAP) is raised in all conditions except: 
Select and explain. 
A. Myelofibrosis, B. Essential thrombocythemia, C. Chronic myeloid leukaemia, D. Polycythemia
C: Chronic myeloid leukaemia
Answer: C: Chronic myeloid leukaemia 
Explanation: Low LAP scores have been associated with CML, PNH, thrombocytopenic purpura, and hereditary hypophosphatasia. In CML regardless of the total white count, the score remains low.