This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, 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: In relation to the oropharyngeal isthmus, there are several aggregations of lymphoid tissue that constitute Waldeyer's lymphatic ring. The most impoant aggregations are the right and left palatine tonsils usually referred to simply as the tonsils. Posteriorly and above there is the pharyngeal tonsil; laterally and above there are the tubal tonsils, and inferiorly there is the lingual tonsil over the posterior pa of the dorsum of the tongue. Ref: BD Chaurasia's HUMAN ANATOMY, Volume 3,4th edition.