Final answer:
To restrict actions such as shutting down systems or network access for users in the TempSales and TempMarketing OUs, you should edit the Security Options category in the Group Policy Object settings.
Step-by-step explanation:
You are managing permissions and restrictions for users within the TempSales and TempMarketing organizational units (OUs) in your domain. The correct Group Policy Object (GPO) category to edit in order to prevent users from shutting down the system or accessing computers through a network connection is the Security Options. This category allows the administrator to control various security settings such as permissions, user rights assignments, and security settings related to the operating system and its features.
By editing the security options, you can configure the policies to restrict the specified activities for all users within these OUs. The GPO category that should be edited to make the necessary changes is User Rights. By modifying the User Rights GPO, you can define the specific actions and tasks that users within the tempsales and tempmarketing OU are allowed to perform on the system.