Answer: D) Her mother is frail and aging.
The best answer for this question is option D. Although the other options present information that also encourages the reader to empathize with the mother, the information was not included simply for this purpose. These details are essential to the plot. The fact that the mother is frail and aging, however, is not essential to the plot, which indicates that the author included this in order to ellicit an emotional response from the reader.