Which mixture is more likely to produce a cleaner violet?

Correct answer: Bluish red and reddish blue

The governing concept is the colour bias of pigments in subtractive mixing. A bluish red and a reddish blue are both directed toward violet, so they contain less yellow-green or other complementary influence that would neutralise the mixture. Yellowish red with greenish blue introduces opposing tendencies; red with yellow makes orange, while blue with orange tends toward a dull neutral. Therefore option B is most likely to produce clean violet.