This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardio thoracic surgery  , Subject name: Surgery
[{'content': 'In Video assisted thoracoscopic surgery for better vision, the space in the operative field is created by : \nSelect and explain. \nA. Self retaining retractor, B. CO2 insufflation, C. Collapse of ipsilateral lung, D. Rib spacing', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Video Assisted Thoracoscopic Surgery (VATS) In contrast to most laparoscopic techniques, the working space for VATS is created not by adding an insufflating gas but rather by removing air from the ipsilateral lung parenchyma causing of the ipsilateral lung. Used for pulmonary decoication, pleurodesis, and lung or pleural biospies. Ref: Sabiston 20th edition Pgno: 355', 'role': 'assistant'}]