This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'At what cervical level spinal cord circumference is maximum \nSelect and explain. \nA. C4, B. C5, C. C6, D. C7', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The cervical enlargement of spinal cord corresponds with the attachments of the large nerves which supply the upper limbs. It extends from about the third cervical to the second thoracic veebra, its maximum circumference (about 38 mm.) being on a level with the attachment of the sixth pair of cervical nerves.', 'role': 'assistant'}]