The Phillips Curve Originally Appeared to Demonstrate a Stable Trade-Off

The Phillips curve originally appeared to demonstrate a stable trade-off between inflation and unemployment.This was later thought to be deficient because

A) it was later recognized that inflation and unemployment were unrelated.
B) the influence on aggregate demand had not been incorporated.
C) changes in unemployment had not been incorporated.
D) the effects of fiscal policy on aggregate demand had not been incorporated.
E) inflationary expectations had not been incorporated.