What should be done to balance a red-violet sample toward red if it appears too violet?

Correct answer: Add a little red

The governing concept is proportional colour mixing. Red-violet is made from red and violet, so a sample that looks too violet needs a small increase in the red component. Add red gradually, mix thoroughly, and compare a test mark before adding more. Option A is correct. Green or yellow would alter the hue in other directions, while black changes value and dullness rather than specifically correcting the red-violet balance.