I think itts virchow
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<span>There are two major theories that will explain on research on colour vision. They are 1. the trichromatic theory also known as the Young-Helmholtz theory 2. opponent-process theory. These two theories explain processes that operate at different levels of the visual system.</span>
I think it’s sperm for your question
It’s b because its shown in the question read it again ,and you’ll see
