This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
Drug which is used in lie detection (truth serum) 
Select and explain. 
A. Glycopyrrolate, B. Solifenacin, C. Hyoscine, D. Acetylcholine
C: Hyoscine
Answer: C: Hyoscine 
Explanation: Hyoscine or scopolamine and thiopentone sodium are the drugs used in lie detection .they are considered as truth serum .under CNS depression it is implied that the patient usually tells the truth Ref: Goodman Gillman 11th ed pg 231-232