Considering a PPF with health care services on the vertical axis and other goods and services on the horizontal axis, the increasing production of health care services in the United States as a result of the aging population represents

A) a movement upward along the PPF.
B) an outward shift of the PPF from the vertical axis.
C) an outward shift of the PPF from the horizontal axis.
D) a movement downward along the PPF.

A