Which option scales the horizontal axis in a plot?

To scale the horizontal axis in a plot, the correct option is the one that specifies the horizontal axis values explicitly. HAXIS=values is designed specifically for this purpose. It allows you to define the scale of the horizontal axis by specifying the minimum and maximum values, as well as tick mark placements if necessary.

The other options serve different functions. VAXIS=values, for instance, is used to scale the vertical axis, not the horizontal axis. CAXIS=color relates to the color of the axis lines or ticks rather than any kind of scaling. CTEXT=color specifies the color of the text labels in the plot, which does not influence the scaling or values displayed on the axes. Understanding these distinctions is crucial for effectively managing data visualization in SAS.