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: Anatomy
[{'content': 'Brachiocephalic vein is formed by \nSelect and explain. \nA. Internal jugular vein and suclavicular vein., B. External jugular vein and suclavicular vein., C. Internal jugular vein and retromandibular vein., D. External jugular vein and retromandibular vein.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]