Refer to the graph of production possibilities frontier (PPF) below, which describes the trade-off between the production of computers and corn. When you move from a production point B to A, what changes need to occur in the production and what happen to the opportunity cost? Please explain. 100 80 PPF 60 COMPUTERS (Millions) 40 X B X F 20 o+ A 0 0 20 40 60 80 100 CORN (Millions of bushels)