Which primary colours are needed to make all three secondary colours?

Correct answer: Red, yellow and blue

The governing concept is the set of primary colours in the traditional artist’s colour wheel. The three primary colours are red, yellow, and blue. Mixing them in pairs gives the three secondary colours: red plus yellow makes orange, yellow plus blue makes green, and blue plus red makes violet. Option C lists the secondary results rather than the required starting colours, while the other choices are not the traditional primary set. Therefore, option A is correct.