1 or 3; maybe 4.
With several assumptions made, ultimately, they’re asking for json, and we should still return json, but what that looks like is up to you. It should be static enough that the person on the other end can write:
If json.grtnode(error) == "unauthorized access"
Do stuff
Ifnyour going to be changing the text with some regularity to contain relevant information for the error (eg, an item ID, that is now invalid), then consider a code/text and additional fields.
Oceania tends to refer to the region, including both Australia, New Zealand, Melanesia, Micronesia, and the many small island nations.
Sometimes, we are “collectivly” treated as a continent, despite being almost all island nations with no land boarders.