This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
[{'content': 'Figure shows the mechanism of action of: \nSelect and explain. \nA. Vinblastine, B. Cisplatin, C. Imatinib, D. Trastuzumab', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (A) VinblastineThe mechanism shows the inhibition of polymerization of tubulin means the drug inhibit the spindle formation. This mechanism is shown by vinca alkaloids like vincristine and vinblastine.Mechanism on spindleDrugsInhibit polymerization of tubulinVincristine, VinblastineInhibit depolymerization of tubulinPaclitaxel, Docetaxel', 'role': 'assistant'}]