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: Medicine
[{'content': 'The ECG of a patient with an artificial pacemaker in the right ventricle shows - \nSelect and explain. \nA. Right bundle branch block with narrow QRS complex, B. Right bundle branch block with broad QRS complex, C. Left bundle branch block with broad QRS complex, D. Left bundle branch block with narrow QRS complex', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]