Final answer:
The exposure required for computed radiography (CR) is similar to a 200 speed film-screen system, which uses a phosphor imaging plate for digital image capture.
Step-by-step explanation:
The amount of exposure required for computed radiography (CR) is similar to a 200 speed film-screen system. Computed radiography is a digital imaging technology used in the field of radiology that uses a phosphor imaging plate to capture images, which can then be processed and viewed digitally. Compared to traditional film-screen systems, CR provides greater dynamic range and is less sensitive to over and under exposure, although it generally requires similar exposure levels to 200 speed systems. Therefore, the correct answer to which film-screen system the exposure for CR is similar would be B. 200 speed.