Final answer:
The optimal viewing of radiographic images requires a Variable light level that can be adjusted for image contrast. Compton scattering uses X-rays. Radio waves are on the low-frequency end of the electromagnetic spectrum.
Step-by-step explanation:
The best light level for viewing radiographic images is d) Variable light level. Radiographs are best observed under a light level that can be adjusted to match the density and contrast of the images. A variable light level allows radiologists to optimize the visibility of subtle details within a radiographic image, which can be critical for accurate diagnosis. Most light boxes and digital viewing screens used in radiology departments have controls to adjust brightness for optimal viewing.
Regarding the electromagnetic spectrum, Compton scattering involves c) X-rays which are electromagnetic waves with much shorter wavelengths than visible light. Furthermore, in the electromagnetic spectrum, radio waves fall on the d) low-frequency side of visible light. The order of the spectrum from low energy to high energy is: a) radio, microwave, infrared, visible, ultraviolet, X-ray, gamma.