Which primary colour should be used in greater quantity to make blue-green?

Correct answer: Blue

The governing concept is hue bias created by unequal proportions in a mixture. Green is made from yellow and blue. To make blue-green, blue must be present in a greater quantity than yellow, causing the green to shift toward blue. Therefore, option C is correct. More yellow would produce yellow-green, red is not one of the two components, and white only changes lightness.