Milton Friedman and Edmund Phelps Contributed Which Insight(s)to Phillips Curve

Multiple Choice

Milton Friedman and Edmund Phelps contributed which insight(s) to Phillips curve analysis?

A) that a "realistic" goal of 7% unemployment and 6% to 7% inflation rates could be achieved
B) that,in the long run,sticky wages and staggered prices prevent unemployment from remaining low
C) that firms and workers care about real wages
D) all of the above
E) none of the above