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 that permits nodding of head while saying yes is? 
Select and explain. 
A. Atlanto-axial joint, B. Atlanto-occipital joint, C. C2- C3 joint, D. C3- C4 joint
B: Atlanto-occipital joint
Answer: B: Atlanto-occipital joint 
Explanation: Atlanto-occipital joint is a synol between skull and C1 veebrae. It permits nodding of head such as flexison and extension (YES movement) and lateral flexion. Atlanto-axial joint is a pivot joint between C1 and C 2 veebrae. It permits rotation of head that is side to side movement (NO movement).