I was asked almost the same question, but was not required to actually name the other schools to which I am applying.  The application required that I state where that school fell in my "top four."  It was definitely number four, but there was no way I would have said that.  I also didn't want to run the risk of seeming like a fake when I listed it in first place.  So, I opted for slot #2.  Not a highly scientific decision-making method, but it's what I did.