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: Medicine
All of the following are seen in polycythemia rubra vera except - 
Select and explain. 
A. Increased Vit B12, binding capacity (>9000 micromols/dL), B. Decreased LAP score, C. Leucocytosis, D. Increased platelets
B: Decreased LAP score
Answer: B: Decreased LAP score 
Explanation: None