Which tools allow the user to create a road that follows the border of a polygon?

The Trace tool is particularly designed for creating features that follow existing geometry or align with particular shapes. When tasked with creating a road along the border of a polygon, using the Trace tool allows the user to click along the edge of the polygon and effectively mimic its outline. This results in a new polyline that closely follows the selected boundary, capturing the shape and nuances of the polygon.

In contrast, the other tools listed serve different purposes. Constrain Perpendicular is used to draw a line that is established at a right angle from another feature, which wouldn’t be appropriate for tracing a polygon's edge. The Right-Angle tool similarly facilitates specific angular constraints, which do not enable following the complex curvature or nuances of a polygon's border. Lastly, the Copy Parallel tool is designed to create a parallel line at a specified distance from an existing feature, rather than directly tracing the geometry of the polygon itself. Each of these tools, while valuable in other contexts, does not have the same capability to accurately replicate the shape of a polygon's border as the Trace tool does.