This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'A 70 kg young athlete was planned for surgery. During anesthesia, vecuronium was not available, so repeated doses of succinylcholine was given intermittently up to 640 mg. During recovery, the patient was not able to spontaneously respire and move limbs. What is the cause? \nSelect and explain. \nA. Pseudocholinesterase deficiency, B. Phase II blockade, C. Muscle weakness due to repeated fasciculations, D. Undiagnosed muscular dystrophy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]