Why would you use a separate Thread command?

Using a separate Thread command to create external threads is appropriate because this command specifically focuses on generating accurate and detailed representations of external threading features. This is crucial in mechanical design, where external threads are utilized for fasteners like screws and bolts. The Thread command can customize the thread type, size, and specifications, ensuring that the model adheres to design standards and can be manufactured correctly.

In contrast, while creating internal threads is also an important process, it typically utilizes different methods or commands specifically tailored for internal threading, which may not be covered by the same commands or parameters used for external threads. The blending of edges is unrelated to threading and is instead focused on creating smoother transitions between edges or surfaces. Simplifying a sketch does not pertain to the Thread command, as its purpose is to add complexity and detail rather than reduce it. Therefore, the emphasis on the Thread command's capability to accurately produce external threads is what makes the choice correct.