This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Apex at of the lung lies at what level? \nSelect and explain. \nA. Above the clavicle, B. Below the clavicle, C. At the level of the clavicle, D. None', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Above the clavicle * Apex lies in the inlet of thorax, 2.5 cm above the clavicle. It is related anteriorly to subclavian artery and vein. Posteriorly it is separated from neck of first rib by (from medial to lateral) sympathetic trunk, fist posterior intercostal vein, superior intercostal artery, and ascending branch of ventral ramus of 1st thoracic nerve.", 'role': 'assistant'}]