Final answer:
Middle-income countries are primarily located in Asia. Asia includes rapidly growing economies which are not yet at the level of high-income nations but have surpassed low-income nations.
Step-by-step explanation:
According to the textbook, the middle-income countries are primarily located in c) Asia. These countries are classified based on economic development and income levels, where they fall between low-income and high-income countries. Asia, with its rapidly growing economies such as China and India, is home to many middle-income countries.
Regarding other geographical and developmental questions in the subject matter:
- The continent home to the majority of HIV-positive cases is d) Africa.
- The region of Africa most directly involved in the Trans-Atlantic slave trade was b) West Africa.
- Confucianism and Taoism have been primarily practiced in c) China.
- Core nations, also known as high-income nations, are listed under option a).
- The type of country with the greatest proportion of young individuals is b) economically underdeveloped countries.
- The Great Famine of 1315-1317 primarily affected a) northern Europe.