Final answer:
The change that should be made when performing an abdomen radiograph on a patient with ascites is to use an abdominal compression device.
Step-by-step explanation:
When performing an abdomen radiograph on a patient with ascites, the correct change to be made is C. Use an abdominal compression device. Ascites is the accumulation of fluid in the abdominal cavity, which can cause the organs to be less visible on the radiograph. By applying an abdominal compression device, it helps to flatten the abdominal contents, making the organs more clearly visible.