This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
[{'content': 'Wide QRS duration is- \nSelect and explain. \nA. >0.8sec, B. >0.9sec Pattern), C. >.12sec, D. All the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: a wide qrs complex by definiton is more than 120 ms The QRS complex duration is wide (>0.12 seconds or 3 small boxes) in every lead. Causes of a widened QRS complex include right or left BBB, pacemaker, hyperkalemia, ventricular preexcitation as is seen in Wolf-Parkinson-White pattern, and a ventricular rhythm. Ref Harrison 20th edition pg 1576', 'role': 'assistant'}]