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': 'Which of the following ECG changes is least likely in a patient with left pneumothorax-(/i//MS \nSelect and explain. \nA. Inversion of Twave, B. Left axis detion, C. Small R wave, D. Electrical altemans', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Abnormal left axis detion was found with left-sided was pneumothorax .Relevant QRS abnormalities (incomplete RBBB and T-wave inversion)in (10%). QRS amplitude in V2-V6 leads was significantly decreased in left-sided pneumothorax. Ref Harrison 20th edition pg 1536', 'role': 'assistant'}]