Which of the following cannot be selected to create Edge Blend features?

Creating Edge Blend features in Siemens NX involves selecting specific geometric entities that can define the transition between surfaces. Part edges, faces, and edges at the intersection of features are all tangible geometrical constructs present in a 3D model that lend themselves to creating smooth transitions, or blends, between adjacent surfaces.

Part edges are the actual boundaries of the solid geometries, while faces provide the planar surfaces from which to derive the blending operations. Edges created at the intersection of these faces are also suitable for Edge Blend features, as they represent the direct connection points between different surfaces that will be blended together.

In contrast, sketch curves are 2D entities that exist within a sketch environment and are primarily used for constructing geometry or guiding 3D features during the modeling process. As such, they do not directly correlate to the 3D edges or faces required for Edge Blend operations, which rely on the three-dimensional aspects of the design to generate the desired blending effect. This is why they cannot be selected for creating Edge Blend features.