This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
[{'content': 'Which nerve is involved in this deformity: \nSelect and explain. \nA. Musculocutaneous nerve, B. Long thoracic nerve, C. Radial nerve, D. Thoracodorsal nerve', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Long thoracic nerveThe deformity shown is Winging of scapula due to Paralysis of serratus anterior.The paralysis of serratus anterior muscle following an injury to long thoracic nerve by stab injury or during removal of the breast tumor leads to the following effects:(a) Protraction of scapula is weakened.(b) Inferior angle and medial border of scapula become unduly prominent particularly when patient pushes his hands against the wall, producing a clinical condition called winging of the scapula.', 'role': 'assistant'}]