This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
This patient presented with jaw pain and was found to have an elevated alkaline phosphatase and a normal serum creatinine. Which one of the following tests would confirm the diagnosis? 
Select and explain. 
A. Bone scan, B. Insulin-like growth factor-1 level, C. Serum calcium, D. Abdominal ultrasound
A: Bone scan
Answer: A: Bone scan 
Explanation: Answer A. Bone scanPaget's disease, acromegaly, and renal osteodystrophy are among the causes of jaw enlargement, visible in this image. An elevated alkaline phosphatase makes Paget's disease the most likely diagnosis; the diagnosis can be confirmed with a bone scan.