This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Larynx, Subject name: ENT
[{'content': 'Which of the following laser is most commonly used in laryngeal surgery \nSelect and explain. \nA. CO2 Laser, B. Nd YAG laser, C. Argon Laser, D. KTP Laser', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Treatment consists of: 1. Radiotherapy 2. Surgery (a) Conservation laryngeal surgery (b) Total laryngectomy 3. Combined therapy. Surgery with pre- or postoperative radiotherapy 4. Endoscopic CO2 laser excision Ref: PL Dhingra; Textbook of EAR, NOSE and THROAT; edition 7; page no 351', 'role': 'assistant'}]