This easiest way to look at this is ending words 'among rich and poor'. It should be 'between rich and poor'. We use between when we are referring to distinction of two things and use 'among' for multiple things. This eliminates options A, C and E.
As for B and D, the original sentence aims to compare 'status' of some litigants with others.
So we choose option D. 'some litigants have a preferred status *to* others'
As for B and D, the original sentence aims to compare 'status' of some litigants with others.
So we choose option D. 'some litigants have a preferred status *to* others'




