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 normal P wave is biphasic in lead: \nSelect and explain. \nA. VI, B. LII, C. aVF, D. aVR', 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer. A (VI): Normal P wave may be seen as a Biphasic wave in lead V1. 'The normal P wave in lead V1 may be biphasic with a positive component reflecting right atrial depolarization followed by a small (<1 mm') negative component reflecting left atrial depolarization' - Harrison Note: The normal P wave is negative (inveed) in lead aVR.", 'role': 'assistant'}]