An artist is using an old spread brush for texture but now needs a clean thin line. What is the best decision?

Correct answer: Select a sound brush with a fine tip

The governing concept is selecting a tool according to the mark required. A spread or worn brush is useful for irregular texture because its separated bristles make broken marks, but it cannot reliably produce a clean narrow line. Option C is correct: a sound brush with a fine, controlled tip is needed. Extra pressure, more spreading, or more paint would usually make the line wider and less precise.