D) South Korea.
The United States and New Zealand are developed nations, for their GDP is high and consistent.
Ethiopia, is a developing nation, as it's GDP is relatively lower than a developed nation (US, Britian, etc).
South Korea, while it is technically a developed nation, is rising quickly, for it's industries are growing (much like the US's industrial age). Therefore, it is classified as a advanced developed nation.
hope this helps
