If blue is mixed into red, in which direction will it shift?

Correct answer: Red-violet

The governing concept is hue shift through colour mixing. Red lies near violet on the colour wheel, so adding blue moves red toward the violet side while retaining a red component; the resulting direction is red-violet. Thus option B is correct. Yellow-orange and yellow-green move toward yellow, while blue-green belongs to a blue–green region and does not describe a red mixture receiving blue.