Problems $21-22.$ The following diagram describes the market for goods and services in an economy.

$21.$ Suppose that initially the economy is at point

A$.$ If a tax reform induces peorple to spend less, the economy would move from point $A$ to $q,$ in the short run, then to $q,$ in the long run.

a$.$ point F$,$ point B

b$.$ point F$,$ point $A$

c point D$,$ point C

d point D$,$ point A