Which type of red and blue is more suitable for making a clean violet?

Correct answer: Blue-biased red and red-biased blue

The governing concept is choosing pigments whose colour biases support the target mixture. For violet, a red leaning toward blue and a blue leaning toward red contribute mainly the two needed violet components, so fewer opposing colour influences are introduced. This usually gives a cleaner, more saturated violet. Option B is correct; the other pairs add yellow, green or unwanted black and white effects.