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
The joint between the atlas and axis is: 
Select and explain. 
A. Ball and socket joint, B. Closely related to the first cervical nerve, C. Allows rotation of the head, D. Supported by the alar ligaments
C: Allows rotation of the head
Answer: C: Allows rotation of the head 
Explanation: First cervical vertebra is known as Atlas.
Second cervical vertebra is known as Axis.

Special joint between Atlas, Axis and Occipital bone:

Atlanto-Occipital joint:

It is a synovial joint - ellipsoid type.
Allows ﬂexion and extension of head on neck (as like nodding up and down).


Atlanto-Axial joint:

It is a pivot type of joint.
Allows rotatory movement of head on neck (as like saying 'NO' - right and left rotation).
The dens of axis forms a pivot, around which the atlas rotates, permitting rotatory motion of  neck possible.