What does changing the size of the part using smart dimensions in an assembly affect?

Changing the size of a part using smart dimensions in an assembly affects driving synchronous part faces. This is because smart dimensions allow users to define the size and shape of a part while maintaining its relationships with other components within the assembly. When a part is resized, the associated synchronous faces that are driven by these dimensions automatically adjust to reflect the new size.

In an assembly context, this is particularly useful as it allows for real-time updates and visual feedback on how changes in one component can impact the overall design. The driving synchronous part faces ensure that the modified dimensions lead to coherent geometry adjustments, facilitating a more efficient design process.

The other choices pertain to different aspects of Solid Edge functionality. For instance, updating sketch relations involves adjustments in the 2D sketch that underpins the 3D model, which may not directly relate to part size changes. Changing material properties reflects the attributes of a part that are independent of its dimension. Lastly, modifying assembly constraints involves changing how parts interact with one another in the assembly environment, which may not necessarily occur when merely resizing a part.