Answer to Question 1
D
Answer to Question 2
The aggregate demand multiplier is an effect that magnifies changes in expenditure plans. So, for example, if some component of expenditure such as investment increases, aggregate demand increases by more than the increase in investment. The aggregate demand multiplier exists because when aggregate demand increases, households' incomes increase. Then the increase in income results in an increase in consumption expenditure, which adds to the initial increase in aggregate demand.