This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neck, Subject name: Surgery
A nerve injured in radical neck dissection leads to loss of sensation in medial side of the arm, nerve injured is:- 
Select and explain. 
A. Long thoracic nerve, B. Thoracodorsal nerve, C. Dorsal scapular nerve, D. Medial cutaneous nerve of arm
D: Medial cutaneous nerve of arm
Answer: D: Medial cutaneous nerve of arm 
Explanation: Nerve injured in radical neck dissection leads to loss of sensation in medial side of the arm, nerve injured is medial cutaneous nerve of arm. The medial cutaneous nerve of arm supplies the skin of the medial aspect of the arm. It is the smallest branch of the brachial plexus, and arises from the medial cord and contains fibres from the eighth cervical and first thoracic ventral rami.