Step 1: In the World Development Reports of the World Bank, countries are classified mainly on the basis of average (per capita) income. Step 2: Countries with a high per capita income are called rich or developed countries, whereas those with a low per capita income are called low-income or developing countries. Step 3: Developed countries also show a LOW infant mortality rate, a HIGH literacy rate and a HIGH net attendance ratio, because of better health and educational facilities; so options (A), (C) and (D) are characteristics of less developed countries. Step 4: Hence the characteristic of a developed country is High Per Capita Income - Option (B).