Which of the following facts supports the trichromatic theory of color vision?

• A. All colors are perceived through a single type of photoreceptor.
• B. Human retinas contain three types of cone cells, each sensitive to different wavelengths of light.
• C. Color blindness always involves the inability to distinguish between black and white.
• D. Color perception is explained by opposing pairs such as red-green and blue-yellow.

Answer: (B)

Verified step by step guidance

1. Understand that the trichromatic theory of color vision proposes that color perception is based on the activity of three types of cone photoreceptors in the retina, each sensitive to different wavelengths corresponding roughly to red, green, and blue light.
2. Identify the key fact that supports this theory: the presence of three distinct types of cone cells in the human retina, each tuned to a specific range of wavelengths.
3. Recognize that the statement 'Human retinas contain three types of cone cells, each sensitive to different wavelengths of light' directly aligns with the core idea of the trichromatic theory.
4. Contrast this with other options: the idea of a single photoreceptor type contradicts the theory, color blindness involving black and white is unrelated, and the opposing pairs explanation belongs to the opponent-process theory, not the trichromatic theory.
5. Conclude that the fact about three types of cone cells supports the trichromatic theory because it explains how different colors are detected through the combination of signals from these three photoreceptor types.