A uniform conducting rod is fixed and allowed to pivot about its center, as shown in the figure. A uniform, positively charged conducting sphere is brought near the upper end of the rod, and the rod rotates clockwise. The rod is then reset to the position shown. The sphere is then brought to point X near the lower end of the rod, and the rod rotates counterclockwise. Which of the following could be true of the charge on the rod? Select two answers.