I researched it before posting a comment, and apparently it is written as one word, so no corrections needed on the quiz.
But it still feels incorrect to me. Maybe because there is such a distinct difference in latin cases/declensions; the difference of going into a house (accusative) and being in a house (ablative).
And maybe because in Old English this was the case as well. Old English has often felt more natural to me because it is grammatically closer to languages I know, than modern english. (Though knowing how a language evolved helps a LOT with getting things right, but sometimes the language has already let go off certain rules, so at times it can be a slight disadvantage as well