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
Which of the following system is most sensitive to atropine 
Select and explain. 
A. Respiratory mucosa, B. Hea, C. Pupil, D. Gastrointestinal motility
A: Respiratory mucosa
Answer: A: Respiratory mucosa 
Explanation: Ref: HL Sharma 3rd ed: Pg no:154 The endpoint for atropinization is dried pulmonary secretions. Tachycardia and mydriasis must not be used to limit or to stop subsequent doses of atropine