This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
[{'content': 'The axis of abduction and adduction of digits passes through the centre of \nSelect and explain. \nA. 2nd metacarpal, B. 3rd metacarpal, C. 4th metacarpal, D. 5th metacarpal', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The third metacarpal is the longest and the axis of abduction and adduction passes through its centre.Ref: Chaurasia; Volume 2; 6th edition; Page no: 31', 'role': 'assistant'}]