What should be controlled most while using complementary colours?

Intensity of contrast and area

Complementary colours are opposite or strongly contrasting colours in a colour system. Placing them together can create energy, emphasis, and visual excitement, but the effect may become harsh or tiring if both colours are equally intense and cover large areas. Good control therefore involves deciding how saturated or bright each colour should be and how much surface each one should occupy. A small intense accent can work better than two equally dominant fields.

Choice B is correct because the intensity of contrast and the area of each colour strongly affect the result. Paper length, brush price, and title size do not control the colour relationship. The aim is not to avoid complementary colours, but to balance their strength and proportion so that they support the subject, mood, and readability of the artwork.

This is a Class 10 Art Education question. Chapter: Fundamentals of Visual Arts. Topic: Elements of Art.