This refused me "Have they the oil and the salt" as the correct translation - but in many dialects of English, "Have they x and y" is a perfectly fine sentence structure - particularly Scots. I got this right, ❤❤❤❤❤❤!
I think the point here is to get us to hear the determinant ending. "They have oil and salt" is, of course, a perfectly good sentence. However, it means something different from "they have the oil and the salt."