This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
The following marker is used to assess the monoclonality in T-cells - 
Select and explain. 
A. Kappa and Lambda chain, B. TCR gene rearrangement, C. CD, D. CD34
B: TCR gene rearrangement
Answer: B: TCR gene rearrangement 
Explanation: Molecular analysis of the rearrangement in T cell population can distinguish polyclonal lymphocyte proliferations from monoclonal expansions. Reference :Robbins basic pathology 9th edition pg no 100: