The triangle stopped first at the the West Indies from Africa where most slaves were pulled off board, then sent on to ports such as New Orleans to be sold. In this context, the closest would be A.
We went back to "Undisturbed Isolationism". We cut ourselves off diplomatically for the most part from many European powers out of fear of being brought into another World War. America was completely and only about America.
Throughout history??? if that is the case then...
Germany-WWII
Japan-WWII
Soviet Union-Cold War
I think it determines your progress at something. It determines on what you can, or need to improve, or possibly change.