The utility that allows you to configure the DHCP service on Gaia from the command line is sysconfig. This utility provides a menu-based interface for configuring various system settings, including network interfaces, routing, DNS, NTP, SNMP, SSH, etc. One of the options in sysconfig is DHCP Server Configuration, which allows you to enable or disable the DHCP service, define DHCP scopes, set lease time, etc. Reference: Gaia Administration Guide R81, page 29.

To grant GAiAAPI permissions for a newly created user, you need to assign the user a permission profile in SmartConsole. A permission profile defines the access level and scope of actions that a user can perform using the GAiAAPI. You can choose from predefined permission profiles or create your own custom profiles. You cannot grant GAiAAPI permissions using dish or bash commands. Reference: [Check Point Security Expert R81 API Reference Guide], page 9.

The command vpn tu tlist shows detailed information about VPN tunnels, such as the peer IP address, encryption domain, IKE phase 1 and phase 2 status, encryption algorithm, and tunnel uptime. The command vpn tu is an interactive tool that allows users to list, delete, or reconnect VPN tunnels. The command cpview is a real-time performance monitoring tool that shows various statistics about the system and network. Reference: VPN Administration Guide, SK97638 - What is cpview Utility and How to Use it

When simulating a problem on a ClusterXL cluster with the command "cphaprob -d STOP -s problem -t 0 register" to initiate a failover on an active cluster member, you can use the command "cphaprob -d STOP unregister" to remove the problematic state and return the cluster to normal operation.
Option A correctly identifies the command that allows you to remove the problematic state, making it the verified answer.

The command cphaprob all show stat is not related to redundancy and functions. This command does not exist in ClusterXL or VRRP. The other commands are valid commands for checking the status of cluster members, interfaces, and synchronization. ClusterXL and VRRP are both high availability solutions that provide redundancy and load balancing for Check Point gateways. Reference: Check Point Security Expert R81 Course, ClusterXL Administration Guide, VRRP Administration Guide