This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Back, Deltoid, and Scapular Region, Subject name: Anatomy
[{'content': 'Serratus anterior is supplied by which nerve? \nSelect and explain. \nA. Long thoracic nerve, B. Spinal accessory nerve, C. Dorsal scapular nerve, D. Axillary nerve', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANSWER: (A) Long thoracic nerveREF: Gray s anatomy 40th ed chapter 46Serratus anterior is innervated by the long thoracic nerve, C5, 6 and 7, which descends on the external surface of the muscle.', 'role': 'assistant'}]