SSO (Single Sign-On) allows users to authenticate once and gain access to multiple systems or services without re-authenticating. This improves user experience and reduces the number of credentials users must manage.
* Source: CompTIA Linux+ XK0-005 Exam Objectives, Domain 4: Security
Reference: Sybex Official CompTIA Linux+ Guide, Chapter 15 - Authentication Methods

The process that will accomplish the task of creating a custom script to run at boot as part of the system services is:
Create a unit file in the /etc/systemd/system/ directory. A unit file is a configuration file that defines the properties and behavior of a systemd service. The systemd is a system and service manager that controls the startup and operation of Linux systems. The /etc/systemd/system/ directory is the location where the administrator can create and store custom unit files. The unit file should have a name that matches the name of the script, such as cleanup.service, and should contain the following sections and options:
[Unit]: This section provides the general information about the service, such as the description, dependencies, and conditions. The administrator should specify the following options in this section:
Description: A brief description of the service, such as "Custom cleanup script".
After: The name of another unit that this service should start after, such as "network.target".
ConditionPathExists: The path of the file or directory that must exist for the service to start, such as "/opt/scripts/cleanup.sh".
[Service]: This section defines how the service should be started and stopped, and what commands should be executed. The administrator should specify the following options in this section:
Type: The type of the service, such as "oneshot", which means that the service will run once and then exit.
ExecStart: The command that will start the service, such as "/bin/bash /opt/scripts/cleanup.sh".
RemainAfterExit: A boolean value that indicates whether the service should remain active after the command exits, such as "yes".
[Install]: This section defines how the service should be enabled and under what circumstances it should be started. The administrator should specify the following option in this section:
WantedBy: The name of another unit that wants this service to be started, such as "multi-user.target", which means that the service will be started when the system reaches the multi-user mode.
Run the command systemct1 enable cleanup. This command will enable the service and create the necessary symbolic links to start the service at boot.
Run the command systemct1 is-enabled cleanup. This command will check the status of the service and confirm that it is enabled.
This process will create a custom script, cleanup.sh, to run at boot as part of the system services. This is the correct process to use to accomplish the task. The other options are incorrect because they either use the wrong directory for the unit file (/etc/default/, /etc/skel/, or /etc/sysctl.d/) or do not create a unit file at all. Reference: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 15: Managing System Services, pages 457-459.

The required changes need to be made to the /etc/login.defs configuration file. The /etc/login.defs file defines the default values for user and group IDs, passwords, shells, and other parameters for user and group creation.
The file contains the directives UID_MIN, UID_MAX, GID_MIN, and GID_MAX, which set the minimum and maximum values for automatic user and group ID selection. The administrator can edit this file and change the values to match the organization's new cybersecurity policies. This is the correct file to modify to accomplish the task. The other options are incorrect because they either do not affect the user and group IDs (
/etc/security/limits.conf or /etc/profile) or do not set the default values (/etc/default
/useradd). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 15: Managing Users and Groups, page 463.

Explanation
The administrator should increase the TimeoutStartUSec configuration for the logsearch.service to resolve the issue. The output of systemct1 status logsearch.service shows that the service failed to start due to a timeout.
The output of cat /etc/systemd/system/logsearch.service shows that the service has a TimeoutStartUSec configuration of 10 seconds, which might be too short for the service to start. The administrator should increase this value to a higher number, such as 30 seconds or 1 minute, and then restart the service. The other options are incorrect because they are not related to the issue. The service is already enabled, as shown by the output of systemct1 is-enabled logsearch.service. The service does not use an OnCalendar configuration, as it is not a timer unit. The service does not use a KillSignal configuration, as it is not being killed by a signal. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Processes and Scheduling Tasks, pages 434-435.

The file id_rsa.pub will be moved to the remote servers for passwordless login. The id_rsa.pub file is the public authentication key that is generated by the ssh-keygen command. The public key can be copied to the remote servers by using the ssh-copy-id command or manually. The remote servers will use the public key to authenticate the user who has the corresponding private key (id_rsa). This will allow the user to log in without entering a password. The other options are incorrect because they are either private keys (id_rsa, id_dsa.pem, or id_ecdsa) or non-existent files (id_dsa.pem or id_ecdsa). Reference: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, page 410.