Final answer:
A collimated white light passing through a prism underwater will display the entire visible spectrum from violet to red, as the light is dispersed into its constituent colors.
Step-by-step explanation:
When a collimated white light is passed through a prism underwater, it experiences dispersion, which separates the light into a spectrum of colors. This phenomenon occurs because the different wavelengths of light are refracted by different amounts as they pass through the prism, with shorter wavelengths bending more than longer wavelengths. As a consequence, one observes a continuous spectrum emerging from the prism, which includes all the colors visible to the human eye, ranging from violet to red. Therefore, the correct answer to what range of colors one sees emerging from a prism under water is a) The entire visible spectrum. Comparable to how raindrops form a rainbow by dispersing sunlight, the prism performs similarly under water with white light.