The correct option is B Allegory
'A story in which ideas are symbolised as people' is Option A, 'Allegory'. Option B, 'Fable' means a short moral story especially with animals as characters. Option C, 'Legend' means a story from an ancient time, that may be true. Option D, 'Parable' means a short simple story that explains especially a moral or religious idea. Thus, options B, C and D are incorrect and the correct word for the given phrase is Option A, Allegory.