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': 'ECG is poor detecting ischemia in areas supplied by wich of the following vessels- \nSelect and explain. \nA. Left anterior descending (LAD), B. Left circumflex (LCx), C. Left Coronary Aery (LCA), D. Right Coronary Aery (RCA)', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Occlusion in the left circumflex aery ECG changes resemble those seen in posterior infarction due to occlusion in the RCA, namely ST-segment elevations in V7-V9 and reciprocal ST-segment depressions in V1-V3, along with high R-waves and positive T-waves in the same leads (V1-V3).but it is poorly detected on ECG Ref Davidson edition23rd pg 460', 'role': 'assistant'}]