Mariana and Hannah are conducting an experiment to test the difference threshold for sense of touch on the forehead. For trial 1, Hannah closes her eyes while Mariana gently touches 2 paperclip points 3 millimeters (mm) apart on Hannah's forehead. Then Hannah reports whether she could feel 1 or 2 points. For each of the next trials, Mariana and Hannah repeat this process, each time with the points 2 more (mm) apart. Hannah reports feeling 1 point until the points are 15 mm apart, when she begins reporting that she feels 2 points. Which inequality best represents the trial numbers in which Hannah feels 2 points?