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
Specific stain for myeloblasts is: 
Select and explain. 
A. Sudan black, B. PAS, C. Myeloperoxidase (MPO), D. LAP
C: Myeloperoxidase (MPO)
Answer: C: Myeloperoxidase (MPO) 
Explanation: Lymphoblast: PAS positive.
Myeloblast: Sudan black, myeloperoxidase and non-specific esterase.

 “MPO is specific for myeloid differentiation. Sudan Black B reactivity is similar to MPO in myeloblasts and monoblasts. The specificity of Sudan Black is less than MPO.”