Refer to the above diagram. The economy is at equilibrium at pointC.What fiscal policy would increase real GDP?

a) Make no change because the economy is at or near its full-employment level of real output.

b) Increase aggregate demand from AD2to AD1by decreasing taxes.

c) Decrease aggregate demand from AD2to AD3by increasing taxes.

d)Increase aggregate demand from AD1to AD2by increasing government spending.