Question

The short-run aggregate supply curve is relatively flat to the left of the full employment output and relatively steep to the right because

resources are difficult to bring into production.
there are shortages of capital.
there are shortages of labor.
there are large amounts of unused capacity and idle human resources.

Answer 1

is it the second one maybe?

Answer 2

or i mean the third

Answer 3

i think may be there are shortages of labor.