This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
[{'content': 'Atropine causes: \nSelect and explain. \nA. Bradycardia, B. Tachycardia, C. Aggravation of heart block, D. Decreased vasomotor tone', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans: b (Tachycardia) Ref: KDT, 6th ed, p. 107The most prominent action of atropine on heart is tachycardia due to the blockade of M receptors on the S A node through which vagal tone decreases heart rate.Other effects of atropine are:CNS: Overall stimulant action,rise in body temperature due to action on hypothalamusCVS: Tachycardia, no marked effect on BPGIT: Decreases intestinal motility by GI smooth muscle relaxationRESP: Bronchodilatation and reduced airway resistanceURINARY: Relaxes bladder and causes urinary retentionEYE: Local anesthetic action on cornea. Mydriasis, Cycloplegia, Abolition of light refelexGLANDS: Decreases lacrimation, Sweating, Salivation by M blockade', 'role': 'assistant'}]