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: Medicine
[{'content': 'The most common site of involvement of spinal TB in children is at which of the following level? \nSelect and explain. \nA. Lower thoracic veebra, B. Upper thoracic veebra, C. Cervical veebra, D. Mid thoracic veebra', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The upper thoracic spine is the most common site of spinal TB in children, the lower thoracic and upper lumbar veebrae are usually affected in adults. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page1347-48', 'role': 'assistant'}]