Contrast

The governing concept is value contrast, meaning the difference between lightness and darkness. Two colours may have different hues but nearly identical values, causing the title and background to blend visually. The artist should compare them in grayscale and increase their light-dark separation if needed. Option C is correct. Brush size, paper thickness and water amount may affect execution, but they do not directly explain unclear tonal separation.

The governing concept is contrast used selectively to create separation. If the shadow and background have nearly the same value or temperature, a small local difference near the object’s edge can clarify its form without destroying natural shading. A heavy black outline looks artificial, a white background is unnecessary, and removing the shadow loses the lighting information that gives the object volume.

The governing concept is contrast and visual hierarchy. A background with greater brightness and sharper edges has stronger visual emphasis, so the eye may move toward it instead of staying on the intended subject. The main figure becomes clearer only when the background is controlled to support it. Brightness does not make paint transparent, and it cannot cause a brush tip to break.