When is a palette knife more effective than a brush in impasto technique?

Correct answer: When thick raised texture is required

Impasto is the application of relatively thick paint so that visible, raised marks remain on the surface. A palette knife can push, spread, pile, and shape such paint without absorbing it like a brush, and pressure or direction can vary the texture. Therefore option A is correct. A fine outline is usually better made with a suitable brush; cutting paper and completely removing paint are unrelated tasks.