One of the Ideas That Found a Permanent Place in Macroeconomics

Multiple Choice

One of the ideas that found a permanent place in macroeconomics after Milton Friedman's presidential address to the American Economic Association in 1967 was that

A) there is not only a temporary tradeoff between inflation and unemployment,but a permanent tradeoff as well.
B) the tradeoff between unemployment and inflation exists only in the long run,but not in the short run.
C) people's expectations about economic events affect economic outcomes.
D) a and b