I don’t know whether you are looking at the original exam question, or an amended version (in the BPP Revision Kit they have added a part (d) which I do not think is very good).
As far as the original exam question is concerned, it is very old (the examiner has changed twice since the question was asked), but it is a good question and there is no reason why something like it could not be asked again. I don’t know why you think it might be unfair.