Friedman and Phelps argued that
A. in the long run, monetary growth did not influence those factors that determine the economy’s unemployment rate.
B. there was a tradeoff between inflation and unemployment in the short-run but not in the long-run.
C. policymakers face a long-run Philips curve that is vertical because the natural unemployment rate is independent of the inflation rate.
D. All of the above
E. A and B, only