Which Statement Describes the Usefulness of the Production Possibilities Frontier

Multiple Choice

Which statement describes the usefulness of the production possibilities frontier?  

A)  The production possibilities frontier demonstrates that, although resources are scarce for individuals, there is no problem of scarcity for society as a whole. 
B)  The production possibilities frontier is based on unrealistic assumptions and therefore has no value as an economic tool. 
C)  The production possibilities frontier is based on simplifying assumptions, but illustrates scarcity, opportunity cost, and economic growth. 
D)  The production possibilities frontier is based on the assumption that technology is constantly changing.