Price level $($CPI$)$

Beginning in Exhibit $6$ from long$-$run equilibrium at point $E_1,$ the aggregate demand curve shifts to $A{D}_2.$ The economy's path to a new long$-$run equilibrium is represented by a movement from:

$E_2$ to $E_1$ to $E_2.$

$E_1$ to $E_3$ to $E_2.$

$E_3$ to $E_1$ to $E_2.$

$E_1$ to $E_2$ to $E_3.$