Which command is used to duplicate a part and then modify it?

The command that is used to duplicate a part and then modify it is the option that allows you to create a copy of an existing part within the same assembly environment. This functionality is particularly useful for assemblies where multiple identical or similar components are needed.

When you utilize this command, the software creates a new part based on the existing one, while retaining the original’s features. This allows you to make modifications to the duplicated part separately. This capability is essential for streamlining design processes, enhancing efficiency, and ensuring that any updates or changes to the model do not adversely affect the original part.

The focus of this command on part duplication and individual modification aligns it closely with the requirement stated in the question, making it the most appropriate choice.