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
Deep injury of neck always involves 
Select and explain. 
A. Platysma, B. Trapezius, C. Sternocleidomastoid, D. Longus colli
A: Platysma
Answer: A: Platysma 
Explanation: Investing layer lies deep to the platysma and surrounds the neck like a collar. The surgeon has to stitch platysma muscle separately so that skin does not adhere to deeper neck muscles otherwise the skin will get an ugly scar. Ref BDC volume 3;sixth edition pg 81