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: Anaesthesia
[{'content': 'In an ICU, following righ subclan rein cannulation for putting CV line, patient developed respiratory distress, dyspnoea, hypotension (BP 100/55) and tachycardia (140/min HR), chest examination revealed diminished air entery and decreased breath sounds on auscultation and hyper resonance on percussion towards right side of chest. Left sided breath sounds were minimally reduced. The probable diagnosis is \nSelect and explain. \nA. Tension pneumothorar, B. Acute MI, C. Air embolism, D. Pulmonary edema', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Tension pneumothorar', 'role': 'assistant'}]