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: Dental
[{'content': "If the patient’s head suddenly falls backward while the patient is supine, the back may assume the position known as postural extension; the legs and arms straighten out, and the neck and back arch. This reflex is? \nSelect and explain. \nA. Asymmetric tonic neck reflex, B. Tonic labyrinthine reflex, C. Startle reflex, D. Moro's reflex", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Asymmetric tonic neck reflex:\xa0If the patient’s head is\xa0suddenly turned to one side, the arm and leg on the side to which the face is turned extend and stiffen.\xa0The limbs on the opposite side flex.\nTonic labyrinthine reflex:. If the patient’s head suddenly\xa0falls backward while the patient is supine, the back may\xa0assume the position known as postural extension; the legs\xa0and arms straighten out, and the neck and back arch.\nStartle reflex:\xa0This reflex, which is frequently observed\xa0in persons with cerebral palsy, consists of sudden,\xa0involuntary, often forceful bodily movements.\xa0\n\nThis reaction is produced when the patient is surprised\xa0by stimuli, such as sudden noises or unexpected\xa0movements by other people.', 'role': 'assistant'}]