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
[{'content': 'Antimitotic drugs of plant source is/are? \nSelect and explain. \nA. Vincristine, B. Isotretinoin, C. Bleomycine, D. Methotraxate', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Vincristine", 'role': 'assistant'}]