This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
In brachial plexus nerve arising from root is 
Select and explain. 
A. Nerve to serratus anterior, B. Axillary nerve, C. Ulnar nerve, D. Suprascapular nerve
A: Nerve to serratus anterior
Answer: A: Nerve to serratus anterior 
Explanation: Nerve to serratus anterior or long thoracic nerve arises from the nerve root of C5-C7. Injury to this nerve causes the condition called winging of scapula due to paralysis of serratus anterior muscle. B D Chaurasia 7th edition Page no: 45