Which pair is more likely to produce a relatively clean violet?

Correct answer: Bluish red and reddish blue

The governing concept is choosing pigments whose colour biases are close to the desired mixture. Bluish red and reddish blue both lean toward violet, so they introduce less unwanted yellow or green influence and are more likely to produce a clean violet. Option A is correct. Orange-red and greenish blue carry opposing impurities, yellow and red tend toward orange, and yellow with blue tends toward green.