This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharynx, Subject name: Anatomy
Waldeyer's ring consists of all of the following except ? 
Select and explain. 
A. Palatine tonsils, B. Pharyngeal tonsils, C. Tubal tonsils, D. Post auricular nodes
D: Post auricular nodes
Answer: D: Post auricular nodes 
Explanation: Ans. is 'd' i.e., Posterior auricular nodes o In relation to the oropharyngeal isthmus, there are several aggregations of lymphoid tissue that constitute the WALDEYER'S lymphatic ring.o The most important aggregations are the right and left palatine tonsils,o Posteriorly and above is the pharyngeal tonsil,o Laterally and above are the tubal tonsilso Inferiorly there is the lingual tonsil over the posterior part of the dorsum of the tongue.