I do not watch this programme or have any idea how much money is involved. If the contestant knew the history of this question, they may have wondered if this was a trick question. I have no idea whether the contestant could have queried the question, but if their answer was exactly correct, or allowing for the "simple" wording, answered Norfolk Broads, two answers could have been correct. (I've not worded that very well). Anyway, had they given either of the answers and had been incorrect, They would have cause to be very upset (20 "upset" marks for each pound lost?)
I think the only recourse would be to be offered another chance on the quiz which I seem to remember happening on another occasion, different quiz I would think.