Ewald Hering was the first to propose the ________ theory of color vision?

A) trichromatic
B) opponent-process
C) dichromatic
D) afterimage

Ewald Hering proposed the opponent-process theory of color vision, which suggests that there are three opposing color pairs: red-green, blue-yellow, and black-white. According to this theory, cells in the visual system are activated by one color in each pair and inhibited by the other, resulting in the perception of color. This theory is different from the trichromatic theory proposed by Young and Helmholtz, which suggests that color vision is based on three types of cones in the retina that are sensitive to different wavelengths of light.