Which relationship allows a sketch edge to be made parallel to the x-axis?

The choice that enables a sketch edge to be made parallel to the x-axis is the one that establishes a direct orientation of the edge relative to the x-axis. Selecting the option that signifies horizontal alignment effectively constrains the edge to run parallel to the x-axis. In Solid Edge, when a sketch entity, such as a line, is designated as horizontal, it is constrained to maintain a parallel alignment with the x-axis regardless of any modifications to the sketch or the dimensions used, preserving its orientation.

The options representing vertical, angle, and concentric relationships serve distinct purposes in sketching and geometry. Specifically, a vertical relationship would align an edge perpendicular to the x-axis, whereas an angle relationship allows for a specific angular orientation, which may or may not align with the x-axis. Concentric relationships are used primarily for circles and arcs, linking their centers or defining relationships between circular figures rather than establishing orientation relative to the x-axis. Consequently, the horizontal relationship is essential for ensuring that a sketch edge runs parallel to the x-axis.