I would have said Bayonne ... famous for their armaments industry giving the world the word bayonet.I can't honestly think of any French towns beginning with K .
It seems a fairly straightforward question that could have several answers, but you don't seem to have told us everything. What's this about a metal connection, and why are you so sure about the K? (Just trying to help !!)
Yes, I know it's sounds complicated. There were 100 questions in the quiz (answered 99) and the clue is that all the questions or answers have a connection with metal (e.g. Q: Dorothy's heartless companion, A: The Tin Man). The initials of the answer are also given - hence 'K'. But I still can't solve this one!