I used "dine" insted of "jeres" and got incorrect. Shouldn't they be both correct?
Yes, they should.
Why is the 'fantastiske' option not valid. It's not literal but quite synonymous imho
Both are correct. I first got an "incorrect" when I used "dine" but then I noticed I had made a mistake elsewhere. I corrected that mistake and tried "dine" again and it worked.