Red, yellow, and blue are traditional primary colours of which system?

Correct answer: Painting and pigment system

The governing concept is the traditional RYB subtractive model used in painting and pigment instruction. In that model, red, yellow, and blue are taught as primary colours from which secondary colours such as orange, green, and violet can be mixed. Therefore, option A is correct. Sound and mathematics are unrelated systems, while black-and-white printing does not use this three-colour pigment arrangement. Modern digital and printing systems may use different primaries, but the question clearly says traditional.