In order to estimate the value of x−y where x and y are real numbers with x>y>0, Xiaoli rounded x up by a small amount, rounded y down by the same amount, and then subtracted her values. Which of the following statements is necessarily correct?<spanclass=′latex−bold′>(A)</span>Her estimate is larger than x−y<spanclass=′latex−bold′>(B)</span>Her estimate is smaller than x−y<spanclass=′latex−bold′>(C)</span>Her estimate equals x−y<spanclass=′latex−bold′>(D)</span>Her estimate equals y−x<spanclass=′latex−bold′>(E)</span>Her estimate is 0