Answer:
I believe it would be an X-ray
Step-by-step explanation:
X-rays are the most common used technology for broken bones.
MRI's are way to expensive, and would take longer time to use, then a X-Ray or CT scan. They get better images of sort tissue, which is what their used for.
CT scan's are used more for back pains, or spinal injuries, rather than a simple broken bone.