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
Diagnostic sign of a fracture 
Select and explain. 
A. Abnormal mobility at fracture site, B. Pain at the fracture site, C. Tenderness, D. Swelling
A: Abnormal mobility at fracture site
Answer: A: Abnormal mobility at fracture site 
Explanation: 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