Final answer:
The book cover uses primary colors, which include red, yellow, and blue, and are often associated with children's toys.
Step-by-step explanation:
The book cover uses c) Primary colors, which are also colors generally associated with children's toys. The primary colors in the context of most art and design are red, yellow, and blue. These colors are fundamental because they cannot be created by mixing other colors together. In contrast, secondary colors such as orange, green, and violet are made by mixing two primary colors. Tertiary colors result from the combination of a primary color with a secondary color, leading to hues like red-orange or yellow-green. Complementary colors are opposite each other on the color wheel, such as red and green or blue and orange, and they tend to stand out boldly next to one another. Universities and sports teams often use complementary colors to create eye-catching designs.