This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
[{'content': 'Which of the following drug causes flaccid paralysis of ascaris? \nSelect and explain. \nA. Albendazole, B. Pyrantel pamoate, C. Piperazine, D. Ivermectin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pyrantel causes activation of nicotinic cholinergic receptors in the worms resulting in persistent depolarization-- slowly developing contracture and spastic paralysis. Worms are then expelled. An anticholinesterase action has also been demonstrated. Because piperazine causes hyperpolarization and flaccid paralysis, it antagonizes the action of pyrantel. Cholinergic receptors in mammalian skeletal muscle have very low affinity for pyrantel. Only 10-15% of an oral dose ESSENTIALS OF PHARMACOLOGY page no. 852', 'role': 'assistant'}]