The Very Wide Range of Colors That Are Seen on the Surface

The very wide range of colors that are seen on the surface of Io results from:

A) frozen ices of sulfur dioxoide, water vapor, and carbon dioxide.
B) the wide range of temperatures, each region emitting its own blackbody spectrum.
C) different chemical compounds, each with its own characteristic color, emitted from the volcanoes.
D) various forms of sulfur, the color of which can vary widely following exposure to a variety of thermal conditions.