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: Forensic Medicine
[{'content': "Widmark's formula is used for measurement of blood levels of: NIMHANS 10; AFMC 11 \nSelect and explain. \nA. Benzodiazepines, B. Barbiturates, C. Alcohol, D. Cocaine", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Alcohol', 'role': 'assistant'}]