Final answer:
Ben can plot a point with one positive and one negative coordinate in Quadrant II, where the x-coordinate is negative and the y-coordinate is positive, or in Quadrant IV, where the x-coordinate is positive and the y-coordinate is negative.
Step-by-step explanation:
If Ben plots a point on the coordinate plane with one coordinate being positive and the other being negative, he can only plot the point in quadrants where the signs of the x and y coordinates are different. In Quadrant II, the x-coordinate is negative and the y-coordinate is positive. In Quadrant IV, the x-coordinate is positive and the y-coordinate is negative. Therefore, the correct answer to which quadrants Ben could plot the point is Quadrant II or Quadrant IV.