Each of the Following Is Something That Economists Know About

Each of the following is something that economists know about business cycles, unemployment, and inflation in the short run except

A) that the basic Keynesian sticky-price model still provides a good guide to the basic determinants of the level of aggregate demand.
B) that the Phillips curve is extremely volatile.
C) that anything that affects aggregate demand affects employment and output.
D) that aggregate supply is the principal determinant of the level of real GDP in the short run.