What Is the Significance of "Exurbia," the Areas Beyond the Older

What is the significance of "exurbia," the areas beyond the older, first ring of suburbs?

A) It is the fastest growing part of America's metropolitan areas.
B) It contains the greatest percentage of the poor.
C) Most of the recent immigrants have settled there.
D) Previously, it was the area most inhabited by those with middle-class manufacturing jobs. Now, these neighborhoods are emptying out.
E) The first bilingual public schools were built in the exurbs of California.