Which of the following actions would you take to open an existing part file in SolidWorks?

To open an existing part file in SolidWorks, the correct action is to navigate to File and then select Open. This command allows you to browse your computer or network for the specific part file you want to work with. Using this methodology directly targets the task of retrieving and displaying an already created file within the SolidWorks environment.

The option related to creating a new part file is not relevant when the goal is to open an existing one, as it would initiate a new design rather than accessing an existing one. Importing typically involves bringing in files from other software or formats into SolidWorks but does not apply to opening files created within the software itself. Meanwhile, saving a file as a different version or format is not applicable when you simply want to access an existing part. Thus, the action of opening an existing part file is specifically performed through the Open command, making it the most appropriate choice.