Which of the following is the best explanation of why it makes sense to refer to the Pacific Northwest as a “region” of the United States? A.
The states share a similar relative location compared to the rest of the nation.
B.
The states share rainforests, coasts, and a shipping-based economy.
C.
The states have similar levels of rain and snow each season.
D.
The states are part of a single ecosystem with similar wildlife .