This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Monitoring in Anesthesia, Subject name: Anaesthesia
[{'content': 'Commonest complication of subclan venous puncture is \nSelect and explain. \nA. Infection, B. Pneumothorax, C. Carotid aery puncture, D. Atrial perforation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pleura being in close proximity subclan cannulation has high incidence of pneumothorax other common problem is malposition of catheter due to its touous course.', 'role': 'assistant'}]