This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
The following anticancer drug is naturally obtained from plants? 
Select and explain. 
A. Cisplatin, B. Tretinoin, C. Vincristine, D. Omalizumab
C: Vincristine
Answer: C: Vincristine 
Explanation: Naturally obtained anticancer drugs are vinca alkaloids, taxanes, L-Asparginase, and camptothecins.Ref: Sharma and Sharma 3rd ed /Pg: 866