This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Medicine
Which of the following drug has the least Marrow suppression 
Select and explain. 
A. Cisplatin, B. Vincristine, C. Cyclophosphamide, D. Methotrexate
B: Vincristine
Answer: B: Vincristine 
Explanation: Mitotic Spindle Inhibitors:Vincristine binds to the tubulin dimer with the result that microtubules are disaggregated. This results in the block of growing cells in M-phaseVincristine is metabolized by the liver, and dose adjustment in the presence of hepatic dysfunction is required. It is a powerful vesicant, and infiltration can be treated by local heat and infiltration of hyaluronidase. At clinically used intravenous doses, neurotoxicity in the form of glove-and-stocking neuropathy is frequent. Acute neuropathic effects include jaw pain, paralytic ileus, urinary retention, and the syndrome of inappropriate antidiuretic hormone secretion. Myelosuppression is not seen.Reference: Harrison&;s Principles of Internal Medicine; 19th edition; Chapter 103e; Principles of Cancer treatment