This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Neoplastic Agents, Subject name: Pharmacology
True about Azathioprine is? 
Select and explain. 
A. It has more anti tumor effect than immunosuppressant effect, B. It is not a prodrug, C. It selectively affects differentiation of T cells, D. It is a pyramidine antimetabolite
C: It selectively affects differentiation of T cells
Answer: C: It selectively affects differentiation of T cells 
Explanation: ANSWER: (C) It selectively affects differentiation of T cellsREF: KDT 6th ed p. 840AZATHIOPRINEPurine antimetaboliteMore marked immunosuppressant effect than antitumour effectIt's a prodrug and converted to more active 6-mercaptopurineSelectively inhibits T cell differentiation and function of T cellsMost important application - graft rejections/e - bone marrow suppression