Rachel drew the two graphs below. Graph R

On a coordinate plane, a line goes through points (0, 0) and (2, 1).
Graph S

On a coordinate plane, a line goes through points (0, 0) and (1, 2).

Rachel says that Graph R has a greater constant of variation than Graph S. Which statement explains whether Rachel is correct?
Rachel is correct; Graph S is nonproportional.
Rachel is correct; Graph R goes farther along the x-axis.
Rachel is not correct; both graphs go through the origin and have the same constant of variation.
Rachel is not correct; Graph S is steeper than Graph R.