How is a tertiary colour formed?

Correct answer: By mixing a primary colour with an adjacent secondary colour

In the traditional colour wheel used in basic art education, a tertiary colour is made by mixing one primary colour with the neighbouring secondary colour. For example, red mixed with orange gives red-orange, while blue mixed with green gives blue-green. Therefore option A is correct. Mixing two primaries produces a secondary colour; black and white create a neutral value, and water changes transparency rather than forming a tertiary hue.