The Natural Rate of Unemployment Is the Rate of Unemployment

The natural rate of unemployment is the rate of unemployment:

A) that occurs when the markup of prices over costs is zero.
B) where the markup of prices over costs is equal to its historical value.
C) that occurs when the money market is in equilibrium.
D) that occurs when both the goods and financial markets are in equilibrium.
E) consistent with both the wage- setting and price- setting equations.