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
During laryngoscopy and endo-tracheal intubation which of the maneuver is not performed – 
Select and explain. 
A. 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
C: The laryngoscope is lifted upwards levering over the upper incisors
Answer: C: The laryngoscope is lifted upwards levering over the upper incisors 
Explanation: Upper incisor teeth have to be protected by a guard and the leverage of teeth should be avoided.

"Loose, filled or capped teeth, especially upper incisors, may be protected by a guard".

— Lee