One such sentence would be this: "The compass was a vital piece of technology that allowed sailors and explorers of all kinds find their position in the world relative to the North Pole".
The correct answer is B. Human Development Index.
The Human Development Index (HDI) takes into consideration several different factors in order to categorize nations as to levels of development. Some of the factors they use are:
A) A country's Gross National Income (GNI)
B) Life expectancy
C) Education of citizens (i.e. college degree, years of schooling for average citizen).