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: Anatomy
[{'content': 'The joint between the atlas and axis is: \nSelect and explain. \nA. Ball and socket joint, B. Closely related to the first cervical nerve, C. Allows rotation of the head, D. Supported by the alar ligaments', 'role': 'user'}, {'content': "Answer: C \nExplanation: First cervical vertebra is known as Atlas.\nSecond cervical vertebra is known as Axis.\n\nSpecial joint between Atlas, Axis and Occipital bone:\n\nAtlanto-Occipital joint:\n\nIt is a synovial joint - ellipsoid type.\nAllows ﬂexion and extension of head on neck (as like nodding up and down).\n\n\nAtlanto-Axial joint:\n\nIt is a pivot type of joint.\nAllows rotatory movement of head on neck (as like saying 'NO' - right and left rotation).\nThe dens of axis forms a pivot, around which the atlas rotates, permitting rotatory motion of\xa0 neck possible.", 'role': 'assistant'}]