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': 'During laryngoscopy and endo-tracheal intubation which of the maneuver is not performed – \nSelect and explain. \nA. Flexion of the neck, B. Extension of Head at the atlanto-occipital joint, C. The laryngoscope is lifted upwards levering over the upper incisors, D. In a straight blade laryngoscope, the epiglottis is lifted by the tip', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Upper incisor teeth have to be protected by a guard and the leverage of teeth should be avoided.\n\n"Loose, filled or capped teeth, especially upper incisors, may be protected by a guard".\n\n— Lee', 'role': 'assistant'}]