Final answer:
The correct answer to which combination is NOT a tertiary color is d) Green-yellow because tertiary colors are obtained by mixing a primary color with a secondary color, and Green-yellow is a combination of two secondary colors.
Step-by-step explanation:
The student's question relates to which of the listed combinations is NOT a tertiary color. Tertiary colors are created by mixing a primary color with a secondary color. The secondary colors are orange (a mix of red and yellow), green (a mix of blue and yellow), and violet (a mix of blue and red). Thus, tertiary colors include mixes such as red-orange or yellow-green. Among the options provided:
- a) Red-orange is a mix of the primary color red and the secondary color orange.
- b) Yellow-green is a mix of the primary color yellow and the secondary color green.
- c) Blue-purple is a mix of the primary color blue and the secondary color violet.
- d) Green-yellow is NOT a tertiary color because it is a mix of two secondary colors, green and yellow, rather than a primary with a secondary.
Therefore, the correct answer to the question is d) Green-yellow.