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: Pharmacology
Which of the following is Bruton's tyrosine Kinase inhibitor ? 
Select and explain. 
A. Gilteritinib, B. Axitinib, C. Ibrutinib, D. Bosutinib
C: Ibrutinib
Answer: C: Ibrutinib 
Explanation: Ibrutinib is a Bruton's tyrosine Kinase inhibitor that inhibits porliferation of B-cells. It is used in the treatment of CLL, Waldenstorm macroglobulinemia.