What is the most suitable correction if blue-violet text is unclear on a dark violet background?

Correct answer: Make the text value lighter

The governing concept is value contrast, which is essential for legibility. Blue-violet text on a dark violet background may have a similar dark value, even though the hues are not identical; the edge therefore lacks sufficient separation. Making the text lighter, option A, increases light-dark contrast and makes the letters easier to read. Darkening the text or matching the values worsens separation, while adding blue to the background does not guarantee a useful value difference.