Is an increase in GDP good for America?

In the case of global pollution, the Nash equilibrium shows that if one nation does not regulate its pollution, other nations:

a. will have to regulate even more strictly. b. will not regulate either because of international price competition. c. will regulate but will bring charges in the WTO against the other . d. will regulate, so they will not harm their own citizens.

A nations capital stock was valued at $500 billion at the start of the year and $575 billion at the end. Consumption of private fixed capital in the year was $35 billion. Assuming stable prices, net investment was:

A.  $35 billion B.  $40 billion C.  $45 billion D.  $75 billion