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 as pre-anaesthetic medication? 
Select and explain. 
A. Atropine, B. Flavoxate, C. Glycopyrrolate, D. Hyoscine
C: Glycopyrrolate
Answer: C: Glycopyrrolate 
Explanation: Glycopyrrolate is used as pre-anaesthetic medication, it is a quaernary amine which doesn't cross BBB and produce unnecessary CNS effects Ref: KDT 6th ed pg 109