"Det finnes et overskudd av vegetarianer i Saudi-Arabia." :D
Ah, so there was a grammatical error in this one, too. I was just amused by the phrase that came up in the multiple-choice question :D
Why is "på olje" wrong? I thought it would be right because of "Vi har et underskudd på gode ideer."
Hmm, I wonder if it's because oil is a concrete noun, while idea is an abstract noun. Any native speakers able to confirm or correct this?