What is the Nash equilibrium of the game?

A firm that has the long-run cost curves shown in the graph below would be able to do or have the following, except:

A. Exploit economies of scale
B. Have an entry barrier protecting it from new entrants into the market
C. Serve an increasing share of the market at lower and lower unit costs
D. Attain lower unit costs by reducing its output level

Refer to the table. An increase in net exports of $10 would:

A.  increase real GDP by $10.
B.  increase real GDP by $30.
C.  decrease real GDP by $10.
D.  decrease real GDP by $30.