<prompt> Antagonism between acetylCholine and atropine is?Competitive antagonismphysiological antagonismNoncompetitive antagonismNone  <response>: Competitive antagonism equilibrium type -The antagonist is chemically similar to the agonist, competes with it and binds to the same site to the exclusion of the agonist molecules. Because the antagonist has affinity but no intrinsic activity no response is produced and the log DRC dose-response curve shifted to the right. Eg; Ach- atropine, morphine- naloxone Ref:KD Tripathi pharmacology 7th edition page.no: 58 