Which mixture will produce a comparatively clean orange?

Correct answer: Yellow-biased red and red-biased yellow

The governing concept is colour bias in subtractive mixing. To make a clean orange, choose a red that leans toward yellow and a yellow that leans toward red, because the two pigments share the desired warm direction and introduce less unwanted blue or green influence. Therefore option B is correct. Blue-biased, violet-contaminated, or already greyed pigments contain competing components that dull the orange.