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
[{'content': 'Which of the following drugs cannot cross the blood placental barrier \nSelect and explain. \nA. Atropine, B. Glycopyrolate, C. Physostigmine, D. Hyoscine hydro bromide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Refer kDT 7/e p116 Glycopyrrolate is a quaternary ammonium compound and is this water soluble and unable to penetrate blood brain barrier', 'role': 'assistant'}]