Which option is NOT a method for changing a user's account settings?

The option that signifies a method not used to change a user's account settings is the one concerning adding a user to a different workspace. User account settings generally involve aspects like roles, usernames, and permissions, all of which directly affect how a user interacts with their account and the resources available to them.

Editing user roles allows the administrator to define the level of access and privileges a user has within Smartsheet, which is a critical aspect of account management. Changing usernames directly alters a user's identification in the system, impacting how the user is recognized and how they log in. Adjusting user permissions fine-tunes what actions a user is allowed to take within the platform, which is essential for maintaining the integrity and security of data.

In contrast, adding a user to a different workspace pertains more to organizational structure rather than individual account settings. While it may affect the projects and tasks that a user can access, it does not alter the user's account preferences or fundamental settings. The process of managing workspaces is focused on collaboration and project management rather than the personal configuration of a user's account.