Which of the following permissions can administrators set on FortiGate?

Administrators can set permissions on FortiGate devices to control access and functionality for different users. The permission type categorized as "Read-and-write" allows users to not only view configurations and settings on the FortiGate unit but also to make changes. This level of access is crucial for administrative roles, as those with read-and-write permissions can perform necessary tasks such as adjusting firewall rules, modifying VPN settings, or updating security policies.

The other options present permission types that are either not applicable in the context of FortiGate access control or do not align with the specific permission capabilities available on the platform. For instance, "Owner-only" might suggest a restriction that doesn't align with the collaborative nature of most administrative setups where multiple admins need shared access. "Guest-access" usually infers limited view-only capabilities, which are not sufficient for administrators who need the ability to make modifications. "Super-user" is more of a role than a permission type and may imply an elevated access level that includes all permissions but is not a standardized term used for permission settings on FortiGate devices.

Thus, the "Read-and-write" option stands out as the clear and applicable choice for defining what administrators can set on FortiGate systems.