"Convergence" has been occurring among the OECD countries because

A) the richer countries give away more of their output than the poorer ones.
B) the poorer countries have had higher growth rates than the richer ones.
C) the richer countries have had higher growth rates than the poorer ones.
D) the poorer countries have had positive growth rates, while the richer ones have had negative growth rates.
E) the procedures for measuring output per capita have been changing.

B