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
Which one of the following laboratory tests differentiates leukemoid reaction from chronic myeloid leukemia ? 
Select and explain. 
A. LAP (leukocyte alkaline phosphatase), B. LCA (leukocyte common antigen), C. MPO (myelo-peroxidase), D. TRAP (tartrate resistant alkaline phosphatase)
A: LAP (leukocyte alkaline phosphatase)
Answer: A: LAP (leukocyte alkaline phosphatase) 
Explanation: None