If a red and green mixture looks too green what should be done to make it a more balanced brown?

Correct answer: Add red gradually

The governing concept is correcting a colour mixture by using the complementary relationship between red and green. If green is dominant, add a small amount of red gradually and mix after each addition. This moves the mixture toward a more neutral brown, so B is correct. Adding green increases the imbalance, white makes a lighter tint, and water changes handling or transparency rather than correcting the green cast.