If a student uses blue and violet to make red-violet what is the correct correction?

Correct answer: Mixing blue and violet produces blue-violet.

On the colour wheel, blue and violet are neighbouring colours. Mixing them produces blue-violet, so option A correctly identifies the needed correction. Red-violet requires red and violet, not blue and violet. Yellow-green, red-orange, and yellow-orange are made from different neighbouring pairs. The useful naming rule is that a tertiary colour normally reflects the two adjacent colours used in its mixture.