The git fetch command downloads commits, files, and refs from a remote repository into the local one. It also updates the remote-tracking branches, which are references to the state of the remote branches. By running git fetch, the administrator can see the new branch created by the development team and then use git checkout to switch to it12.

Terraform is a tool for building, changing, and managing infrastructure as code in a cloud-based environment. Terraform uses configuration files to describe the desired state of the infrastructure and applies changes accordingly. Terraform supports various cloud providers, such as AWS, Azure, Google Cloud Platform, and more.
To validate changes before they are applied to the cloud-based environment, the administrator can use the terraform plan command. This command will compare the current state of the infrastructure with the desired state defined in the configuration files and show what actions will be performed to achieve the desired state. This command will not make any changes to the infrastructure but only show a plan of changes. The statement D is correct.
The statements A, B, and C are incorrect because they do not validate changes before they are applied to the cloud-based environment. Ansible is another tool for automating infrastructure management, but it does not have a plan command. Git clone and git pull are commands for working with git repositories, which are used for version control of code. Reference: [How to Use Terraform to Manage Cloud Infrastructure]

The command that will set the sticky bit on a directory called devops with 755 file permission is chmod 1755 devops. This command will use chmod to change the mode of the directory devops to 1755, which means that the owner has read, write, and execute permissions (7), the group has read and execute permissions (5), and others have read and execute permissions (5). The first digit 1 indicates that the sticky bit is set on the directory, which is a special permission that prevents users from deleting or renaming files in the directory that they do not own.
The other options are not correct commands for setting the sticky bit on a directory. The chown -s 755 devops command is invalid because chown is used to change the owner and group of files or directories, not their permissions. The -s option for chown is used to remove a symbolic link, not to set the sticky bit. The chown 1755 devops command is also invalid because chown does not accept numeric arguments for changing permissions. The chmod -s 755 devops command will remove the sticky bit from the directory devops, not set it. Reference: chmod(1) - Linux manual page; How to Use SUID, SGID, and Sticky Bits on Linux

The lsscsi command can list the SCSI devices on the system, along with their size and device name. The -s option shows the size of each device. The administrator can look for the device that has a size of 500G and note its device name. See lsscsi(8) - Linux man page and How to check Disk Interface Types in Linux.
Reference
1: https://linux.die.net/man/8/lsscsi
2: https://www.golinuxcloud.com/check-disk-type-linux/

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.