This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Airway, Subject name: Anaesthesia
[{'content': 'Best position for intubating on adult patient when using macintosh laryngoscope- \nSelect and explain. \nA. Shoulder elevated, B. Flexion of the lower cervical spine and extension of head, C. Flat on the bed, D. Hyperextension of neck', 'role': 'user'}, {'content': 'Answer: B \nExplanation: This is called morning sniffing position. There is movement on two joints atlantoccipital jt and neck joint . Atlantoccipital joint is extended. Neck joint is flexed.', 'role': 'assistant'}]