If Real GDP Is Greater Than Potential GDP,the Output Gap

If real GDP is greater than potential GDP,the output gap could be eliminated by
1) an increase in government purchases;
2) an upward shift in the AE curve;
3) a reduction in the money supply.

A) 1 only
B) 2 only
C) 3 only
D) 1 or 2
E) 1 or 2 or 3