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: Anatomy
[{'content': 'After radical mastectomy there was injury to the long thoracic nerve. The integrity of the nerve can be tested at the bedside by asking the patient to \nSelect and explain. \nA. Shrug the shoulders, B. Raise the arm above the head on the affected side, C. Touch the opposite shoulder, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Long thoracic nerve innervates Serratus anterior. Serratus anterior originates from outer surface of upper 8 ribs and inserts onto inferior angle and medial border of scapula. \nActions :\n\nIt rotates the scapula to help in overhead abduction.\nSteady the scapula to carry weight.\nPushing of arm forward in horizontal position.\nHelps in forced inspiration.', 'role': 'assistant'}]