The lower layer is dry during glazing yet the transparent upper colour looks streaky. What is the likely cause?

Correct answer: The brush is unevenly loaded and the strokes are overworked

The governing concept of glazing is a thin, transparent, even film applied over a dry layer without excessive disturbance. An unevenly loaded brush deposits different amounts of pigment, and repeated brushing redistributes the film into visible streaks; therefore option A is correct. A dry lower layer is normally desirable, while white paper and transparency alone do not cause streaking.