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': 'Right superior intercostal vein drains into \nSelect and explain. \nA. Brachiocephalic vein, B. Azygos vein, C. Inferior venacava, D. Hemizygos vein', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The right superior intercostal vein drains the 2nd, 3rd, and 4th posterior intercostal veins on the right side of the body. It flows into the azygos vein. The left superior intercostal veins drains the 2nd and 3rd posterior intercostal veins on the left side of the body. It drains into the left brachiocephalic vein B D CHOURASIAS HUMAN ANATOMY UPPER LIMB THORAX VOLUME, 1 SIXTH EDITION, page no,221', 'role': 'assistant'}]