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
Widmark's formula helps in the measurements of blood level of: 
Select and explain. 
A. Barbiturates, B. Cocaine, C. Alcohol, D. Benzodiazepines
C: Alcohol
Answer: C: Alcohol 
Explanation: C i.e. Alcohol