This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc. (W.B.C), Subject name: Pathology
Beta-2 -microglobulin is a tumor marker for 
Select and explain. 
A. Multiple myeloma, B. Lung cancer, C. Colonic neoplasm, D. Choriocarcinoma
A: Multiple myeloma
Answer: A: Multiple myeloma 
Explanation: Ans. (a) Multiple myeloma(Ref: Robbins 9th/pg598-602)Serum b2 microglobulin level <3.5mg/L indicates good prognosis, in multiple myeloma.