"She is paying only for the wine."
Translation:היא משלמת רק על היין.
I don't like how they give you phrases, which you never learned before. At least I can't remember having seen עבור for על in the lessons.... >>
As near as I can tell the multiple choice options seem to be generated from all acceptable translations of a sentence. When translating a sentence freehand, it allows you to use words that haven't been learned in the lessons in case someone with prior knowledge tries to use them, so those answers are marked acceptable and get thrown in the pool for multiple choice.
True, it's a bit annoying, but it seems to me that it's a general issue with Duolingo. In other languages, you also often get new words and phrases in review exercises, not in new lessons as it is supposed to be.