If Full-Employment GDP Is Equal to $4

Multiple Choice

If full-employment GDP is equal to $4.2 trillion,what does the long-run aggregate supply curve look like?

A) It is a horizontal line at $4.2 trillion of GDP.
B) It is a vertical line at a level of GDP below $4.2 trillion.
C) It is a vertical line at $4.2 trillion of GDP.
D) It is a vertical line at a level of GDP above $4.2 trillion.