Demand$-$pull infilation occurs when a:

A$.$ leftward shift of aggregate demand causes firms to raise their prices in an attempt to make up for a lower sales volume.

B$.$ rightward shift of aggregate demand causes the short$-$run equilibrium level of output to exceed full employment output.

C$.$ rightward shift of short$-$run aggregate supply causes the short$-$run equilibrium level of output to exceed full employment output.

D$.$ leftward shift of long$-$run aggregate supply causes a recession.