which one is the right answer?

The long-run economic growth model assumes that:

a)

the long run takes a long time to arrive.

b)

the economy is at all times at full employment.

c)

the economy always moves toward an equilibrium at full employment.

d)

macroeconomic equilibrium at full employment is only a theory and has little to do with reality.The long-run aggregate supply curve:

a)

shows the economy reaching an equilibrium at the natural rate of unemployment.

b)

shows prices, wages, and interest rates to be inflexible.

c)

is horizontal.

d)

can never shift.