What does the 'vertical' option do when applied to a sketch edge?

The 'vertical' option in sketching is used to constrain an edge or line such that it becomes perpendicular to the horizontal plane, effectively aligning it with the y-axis in the Cartesian coordinate system. When you apply the vertical constraint, it ensures that the edge maintains this orientation regardless of other modifications made to the sketch, providing greater control over the geometry.

By enforcing a vertical alignment, it contributes to the organization and stability of the sketch, making it easier to design complex shapes while adhering to desired dimensional relationships. This is particularly important in parametric modeling, where relationships between entities can affect the overall design.

The other options do not accurately describe the function of the vertical constraint, as they either reference different axes or impose unrelated restrictions on the edge's orientation or position. The vertical constraint’s specific role is to fix the edge's alignment relative to the y-axis, separating it from options that may suggest different orientations or positional constraints.