it is important to have atleast 5 success stories in your back pocket they will ask questions basically similar just with different situations. i was greatly unprepared for this section, make sure to make these answers as relevant as possible.
Again keep a good "story" pool and make sure to answer the question in the S.T.A.R. format. you will likely have a briefing you've prepared before proceeding with the interview. DO bring relevant information to show to the interviewer and make sure you research the hell out of your topic you will have to convince them of whatever case you are making.