This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy and physiology of bone and fracture healing, Subject name: Orthopaedics
[{'content': 'Diagnostic sign of a fracture \nSelect and explain. \nA. Abnormal mobility at fracture site, B. Pain at the fracture site, C. Tenderness, D. Swelling', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Diagnostic sign of a fracture is abnormal mobility at fracture site. Pathognomic sign of traumatic and fresh fracture is crepitus. ref:maheswari ,5thedition,page no.12', 'role': 'assistant'}]