Some Agricultural Sub-Saharan Nations of Africa Have Overfarmed and Overgrazed

Multiple Choice

Some agricultural sub-Saharan nations of Africa have overfarmed and overgrazed their land to the extent that significant portions of it have turned into desert. This suggests that

A) the production possibilities curves of such nations are more bowed out from the origin.
B) the production possibilities curves of such nations have shifted inward.
C) the production possibilities curves of such nations have shifted outward.
D) these nations are operating at some point outside of their production possibilities curves.