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
All are infraclavicular branches of brachial plexus except? 
Select and explain. 
A. Ulnar nerve, B. Long thoracic nerve, C. Axillary nerve, D. Thoracodorsal nerve
B: Long thoracic nerve
Answer: B: Long thoracic nerve 
Explanation: The long thoracic nerve arises from the root stage of the brachial plexus. They are present behind the scalenus anterior and scalenus medius in the neck. The ulnar nerve is a branch of the medial cord. The thoracodorsal and axillary nerve are branches of the posterior cord. The cords of the brachial plexus are formed in the cervicoaxillary canal and hence are infraclavicular in position Reference: Clinical Anatomy for students, a problem-solving approach, Neeta v Kulkarni, 2nd edition, page no.98, 99