Which of the following colors symbolizes prosperity on the North Dakota state flag?

The correct choice is yellow, which symbolizes prosperity on the North Dakota state flag. In heraldry and symbolism, colors often have specific meanings. Yellow typically represents wealth, prosperity, and optimism, reflecting the agricultural richness and natural resources of North Dakota.

The state flag features an eagle, which is also a symbol of strength and freedom, adding to the overall message of prosperity and vitality. The other colors present on the flag have their own symbolic meanings—red can signify courage or valor, green is often associated with growth or fertility, and black may denote constancy or endurance. However, yellow specifically stands out in the context of representing prosperity, making it the color associated with this idea on the flag.