This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Forensic Toxicology - Concepts, Statutes, Evidence, and Techniques, Subject name: Forensic Medicine
[{'content': 'Which is not a derivative of cannabis? \nSelect and explain. \nA. Heroin, B. Charas, C. Ganza, D. Bhang', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) HeroinRef.: Parikh 6th ed. 10.54', 'role': 'assistant'}]