A production possibilities curve that is concave from the origin shows that

Select one:

A. supply increases when demand increases.

B. demand for both goods changes as you increase demand for one good.

C. as you increase demand for one good, you must give up the demand for the other good.

D. as you increase the production of one good, you must give up increasing units of the other good.

E. as you increase demand for one good, you must give up the supply of the other good.