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: Surgery
[{'content': 'Commonest site of branchial cyst: September 2012 \nSelect and explain. \nA. Lower 1/3rd of sternomastoid on anterior border, B. Lower 1/3rd of sternomastoid on posterior border, C. Upper 1/3rd of sternomastoid on anterior border, D. Upper 1/3rd of sternomastoid on posterior border', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C i.e. Upper 1/3rd of sternomastoid on anterior border Branchial cyst MC site: Upper pa of neck, Wall is made of: Lymphoid tissue', 'role': 'assistant'}]