Rich country to poor country migration is relatively uncommon

Over the past fifty years, there has been substantial closure of the gap in real GDP per person between which of the following groups of countries?

A) the United States and Central and South America B) Africa and Western Europe C) Central and South America and Africa D) the United States and Japan

An increase in income will tend to cause which of the following?

A) an increase in the monetary base (H) B) a reduction in H C) an increase in the interest rate D) a reduction in the money multiplier E) none of the above