The Phillips Curve graph is a model derived from the AD-AS graph, but not identical to it. What is the general principle represented by the Phillips Curve? a. There is a tradeoff between inflation and unemployment; policies that reduce one will increase the other. b. There is a tradeoff between unemployment and economic growth; policies that reduce one will increase the other. c. Less unemployment is always better, because an economy is more efficient when it employs more people. d. The real aggregate supply curve is a curve, not a right angle with a sharp "corner