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: ENT
The lymphatic drainage of pyriform fossa is to 
Select and explain. 
A. Prelaryngeal node, B. Parapharyngeal nodes, C. Mediastinal nodes, D. Upper deep cervical nodes
D: Upper deep cervical nodes
Answer: D: Upper deep cervical nodes 
Explanation: Lymphatic drainage of Hypopharynx 1) Pyriform sinus drains into upper jugular chain and then to deep cervical group of lymph nodes. 2) Postcricoid region drains into parapharyngeal and paratracheal group of lymph nodes. 3) Posterior pharyngeal wall drains into parapharyngeal lymph nodes and finally to deep cervical lymph nodes. Ref:- Tuli; pg num:- 231, 232