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': 'Cricothyrotomy is converted to tracheostomy at an early stage to \nSelect and explain. \nA. Avoid subglottic stenosis, B. Avoid hypoxia, C. Prevent damage to epiglottis and vocal cords, D. Facilitate oxygenation', 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer: a) Avoid subglottic stenosis (DHINGRA 6th ED, P-320)Cricothyrotomy or Laryngotomy or Mini-tracheostomy:* This is a procedure for opening the airway through the cricothyroid membrane.* Patient's head and neck is extended, lower border of thyroid cartilage and cricoid ring are identified.* Skin in this area is incised vertically and then cricothyroid membrane cut with a transverse incision.* This space can be kept open with a small tracheostomy tube or by inserting the handle of knife and turning it at right angles if tube is not available.* It is essential to perform an orderly tracheostomy as soon as possible because perichondritis, subglottic oedema and laryngeal stenosis can follow prolonged laryngotomy", 'role': 'assistant'}]