Which is the most suitable practical test of understanding primary colours?

Correct answer: Mix two primary colours in different ratios and identify the results

The governing concept is practical demonstration of colour knowledge rather than simple recall. Mixing two primary colours in different ratios requires the learner to apply the colour system, observe how the resulting secondary colour changes in hue or intensity, and identify the results. Thus option A is the strongest test. Writing names checks memory only, drawing circles checks shape-making, and measuring a brush checks a tool property, not colour understanding.