Which mixture is correct for making a light tint of yellow-orange?

Correct answer: Yellow-orange and white

The governing concept is the difference between a tint and a shade. A tint is produced by adding white to a hue, so mixing white with yellow-orange makes a lighter version of the same colour. Therefore, option A is correct. Black would produce a darker shade, while blue or green would alter the hue and may reduce its clarity rather than simply making a light tint. The key rule is: tint equals colour plus white.