To start, what is the conclusion concerning words for colours? Speakers of languages that have fewer basic words for colours than English has must be perceptually unable to distinguish as many colours as speakers of English can distinguish.
What is the assumption here? That language influences what we are able to perceptually distinguish. The author is essentially saying that, if a language does not have a basic word for a particular shade, then the speakers of that language must not be able to perceive that colour.
Answer choice (B) provides support for this assumption by telling us that each language has a different basic word for each sensory quality that its speakers can perceptually distinguish. In other words, each sensory quality that can be distinguished has a corresponding basic word.
This supports the conclusion that each colour that can be distinguished should also have a corresponding basic word.
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