If a poster needs quick attention which colour relation may be better?

Complementary contrast

Correct answer: B, complementary contrast. A poster must often communicate quickly, so a clear difference between colours can help important lettering, symbols, or images stand out. Complementary colours are strongly separated in colour relationships, and their contrast can attract the eye when used carefully. A is wrong because an all-grey scheme may be quiet and unified, but it does not normally provide the strongest immediate colour contrast. C is wrong because very little value difference makes adjacent areas harder to separate visually. D is wrong because muted analogous colours are close in hue and generally create harmony rather than a sharp visual signal. B is correct, though good design still requires readable value contrast, suitable proportions, and restraint; excessive intensity can reduce comfort or legibility. Memory cue: posters need a visual signal—strong contrast helps emphasis, while harmony supports calm unity.

This is a Class 10 Art Education question. Chapter: Colour Study. Topic: Complementary colours.