Which command is used to eliminate unnecessary lines from a sketch?

The command that is used to eliminate unnecessary lines from a sketch is Trim. This command is particularly important in the sketching and drawing processes, as it allows users to selectively remove portions of lines, arcs, or other sketch entities that extend beyond their desired endpoints or overlap with other elements.

Using the Trim command ensures that the sketch stays clean and organized, which is essential for creating accurate designs. This process is much more efficient because it allows for specific portions to be removed without affecting the entire object or layout. Moreover, Trim often provides a more intuitive interactive experience, letting users click on portions of lines to trim them instantly.

The other options, while they might seem relevant at a glance, do not serve the same purpose. For instance, Erase and Delete generally remove entire objects or entities rather than offering a selective trimming feature, which can be less efficient in a detailed sketch. The term Clean, while intuitive, is not an official command used in software like AutoCAD or similar tools, making it irrelevant in this context. Thus, Trim is the ideal command for refining sketches by removing unnecessary lines.