Xiao Zhang scores better than Xiao Li, but because Xiao Ming scores better than Xiao Hong, Xiao Zhang scores better than Xiao Hong. Except for any of the following, as a necessary prerequisite for the above statement to be true? ['Xiao Zhang and Xiao-Ming score equally well.', 'Xiao Li has better grades than Xiao Hong.', 'Xiao Zhang scores better than Xiao Ming.', 'Xiao Ming has better results than Xiao Zhang.']