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: Surgery
Structures preserved	in functional radical dissection of the neck, except 
Select and explain. 
A. Internal jugular vein, B. Sternomastoid, C. Lymph nodes, D. Accessory nerve
C: Lymph nodes
Answer: C: Lymph nodes 
Explanation: None