This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pneumothorax, Subject name: Medicine
[{'content': 'Tension pneumothorax results in all except? \nSelect and explain. \nA. Respiratory alkalosis, B. Decreased cardiac output, C. Decreased venous return, D. Absent breath sounds', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tension Pneumothorax :- Reduced blood supply to lungs | Affected lung has collapsed and contralateral lung will not be able to do the work of both the lungs. | This results in carbon dioxide retention ultimately leading to Respiratory Acidosis', 'role': 'assistant'}]