Which of the following was originally used to measure bone density?

X-rays used to measure bone density.

Explanation:

The bones density test measured by the X-rays, it measures the content of calcium and other bone minerals that are packed into the segment of bone. Most commonly used parts of bone for testing are spine, hip, occasionally and the forearm. It is generally done to know the chances of osteoporosis. More the bone minerals, more will be density. More density means the higher bone strength. Before the test, a person should avoid having calcium supplement.