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': 'Which of the following ECG changes is least likely in a patient with left pneumothorax- \nSelect and explain. \nA. Inversion of Twave, B. Left axis deviation, C. Small R wave, D. Electrical alternans', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]