Why is it "jij zal" in the translation but it accepted "jij zult" ... ??? o.e
Because both 'jij zal' and 'jij zult' are correct. 'Zullen' is an irregular verb. (Note that only 'hij zal' is correct, not 'hij zult'.)
Wait... So is it correct in all cases or just this one? Do people tend to prefer zal/zult?
They're correct in all cases, and are both used equally (I think). I prefer 'jij zal', though. (Because, 'jij zult' sounds like a command to me...)