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
Which of the following structure is preserved in Type I Modified radical neck dissection? 
Select and explain. 
A. Sternocleidomastoid, B. Spinal accessory nerve, C. Level IX lymph node, D. Internal juglar Nein
B: Spinal accessory nerve
Answer: B: Spinal accessory nerve 
Explanation: Modified radical neck dissection involves removal of I - V lymph nodes & 
In type 1: Spinal accessory nerve is preserved.
In type 2: Internal juglar vein is preserved.
In type 3: Sternocleidomastoid.