Except it's not the right answer. Ireland is bigger. (Borneo counts; so does Ireland). Other answers are also wrong as they are archipelagos, not islands. New Guinea is the right answer for Oceania, so I reckon that only two of the given answers are correct (Greenland and Borneo)!
Could you add some clarity in the description of what qualifies as a non-sovereign island? I think it is a bit unclear right now and could definitely add to the quality of the quiz.
*types Greenland*
*thinks*
"...Aw, nuts."
Seriously though, neat idea!