What will likely happen to the slope or position of the $\mathrm{AD}$ curve in the following circumstances?
a. The exchange rate changes from fixed to flexible.
b. A fall in the price level doesn't make people feel richer.
c. A fall in the price level creates expectations of a further-falling price level.
d. Income is redistributed from rich people to poor people.
e. Autonomous exports increase by 20 .
f. Government spending decreases by $10 . \mathrm{LO} 2$