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': 'The toxic effect of beta receptor antagonists includes all the following EXCEPT \nSelect and explain. \nA. Hypoglycemic episodes in diabetes, B. Worsening of preexisting asthma, C. Ischemic cardiac episode on abrupt discontinuation, D. Precipitate migrainic effect', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]