Answer: a. shift the AE curve down.
Explanation:
The Aggregate Expenditure curve shows the amount of spending on final goods and services being done in an economy. If people are saving more, this means they are spending less and so the Aggregate expenditure will have to express this.
This will lead to the AE curve shifting down to represent that Aggregate expenditure has fallen and this will also lead to a fall in real GDP as shown on the curve.