Final answer:
Cascadia is the name of the region along the Pacific coast that became popular in the 1990s, comprising parts of the U.S. states and Canadian territory along the Pacific Northwest.
Step-by-step explanation:
The name of the proposed region along the Pacific coast that gained popularity in the 1990s is Cascadia. This region includes the coastal portions of California, Oregon, and Washington, in the United States, as well as parts of British Columbia in Canada. Different from the other options like Ecotopia, Pacifica, and Oceania, Cascadia refers to a bioregional and proposed country that encompasses this Pacific Northwest area.