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
The biochemical marker of lymphocytic leukemia is - 
Select and explain. 
A. Enolase, B. Peroxidase, C. Choline esterase, D. Periodic and Schiff
D: Periodic and Schiff
Answer: D: Periodic and Schiff 
Explanation: None