What Is the Relationship Between a Country's Wealth and Other

What is the relationship between a country's wealth and other measures of well-being such as life expectancy and literacy?

A) In rich countries, people typically live into their late seventies, while in poor countries people typically live only until their fifties or early sixties.
B) In rich countries, as well as in poor countries, most people can read.
C) Poor countries tend to have higher infant mortality rates than do rich countries; therefore, population in poor countries increases at a lower rate.
D) In rich countries income inequality is less than in poor countries.