The correct answer is A. An infection that migrates via the bloodstream
Explanation:
Osteomyelitis is a serious condition, in which an infection develops in bones. This causes symptoms such as pain, inflammation, and can lead to the spread of the infection to other tissues or bone necrosis if it is not treated. In terms of causes, this condition develops when the bone is exposed to bacteria or similar that causes the infection, this can occur during surgeries or fractures. However, the most common source of infection is via bloodstream this means the bacteria or germ is in the blood and it enters the bone through the bloodstream. Also, once the bacteria or germ is in the bone it causes the infection.