In which situation would a rigger brush be more useful than an ordinary liner brush?

Correct answer: For making long continuous fine branches

The governing concept is matching brush design to the required stroke. A rigger has unusually long, fine bristles that can hold a useful quantity of paint and release it in a continuous narrow line. This makes it especially suitable for extended branches, wires, stems, or similar details. A large sky needs a broad brush, thick square marks need a flat or wide brush, and dot printing does not use the rigger’s long-line advantage. Therefore, option A is correct.