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': 'This antihistaminic drug can cause cardiac arrhythmia at high dose by blocking cardiac K +  channels. It is most likely to be: \nSelect and explain. \nA. Levo-cetrizine, B. Fexofenadine, C. Astemizole, D. Loratidine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]