What happens next in this paragraph?

How to understand bone density score
Understand the differences between peripheral and centralized bone scans.
Besides cost and ease of screening, these tests also vary in accuracy. Some physicians will start with the peripheral test and only conduct the centralized test if the first screen indicates poor bone density.
Possible answers:
(a). Others will conduct a centralized test to measure whether there is poor bone density in the blood. This test is called the ultrasonic echocardiogram..
(b). Other tests will hear errors or low score numbers that will mark poor quality. Still others will conduct only the centralized test..
(c). Others may want to vary tests by 10 percent. Occasionally, adjustments will be made and some tests result in success..
(d). Peripheral machines are small and portable, and they check bone density on the periphery of your skeleton, such as finger bones or the heel. They are much cheaper but not always a good indicator of bone health in bones that are the most likely to break..
(d).