Which consistency of poster colour is most suitable for creating an even layer?

Correct answer: Medium and smooth

The governing concept is workable paint consistency: the colour should flow from the brush while retaining enough body and opacity. A medium, smooth mixture spreads evenly and can be controlled, so option B is correct. Very dry paint drags and leaves gaps or brush marks; very watery paint runs, becomes thin and may streak; a grainy mixture produces an irregular texture instead of a uniform coating. Mix and test before applying.