An Economy's Production Possibilities Frontier _____

An economy's production possibilities frontier _____

A) helps explain the immense complexity of the real economy.
B) demonstrates that there is no problem of scarcity for society as a whole.
C) is based on unrealistic assumptions and has no value as an economic tool.
D) is based on simplifying assumptions, but is still useful for illustrating scarcity, opportunity cost, and economic growth.
E) is based on the assumption that technology is constantly changing.