Based on the output of the image sent by the user, Joe is unable to log in to the Linux system because his account has been locked due to too many failed login attempts. The pam_tally2 -u joe -r command will resolve this issue by resetting Joe's failed login counter to zero and unlocking his account. This command uses the pam_tally2 module to manage user account locking based on login failures. The usermod -s /bin/bash joe command will change Joe's login shell to /bin/bash, but this will not unlock his account. The passwd -u joe command will unlock Joe's password if it has been locked by passwd -l joe, but this will not reset his failed login counter or unlock his account if it has been locked by pam_tally2. The chage -E 90 joe command will set Joe's account expiration date to 90 days from today, but this will not unlock his account or reset his failed login counter. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18:
Securing Linux Systems, page 537.

First, the administrator should build the container image using the command docker build -t Test- Container, which creates a Docker image with the specified configuration. To run the container and expose port 9000, the correct command is docker run -p 80:9000 Test-Container, which maps the container's port 9000 to port 80 on the host machine, making the service accessible externally on port 80.

The SSH configuration option PermitRootLogin prohibit-password prevents the root user from logging in with password authentication. This setting means root cannot use a password to log in via SSH; only key- based authentication is permitted for root. The administrator can still log in as root locally, which is not affected by this SSH configuration. To allow SSH access as root, the administrator must use an SSH key instead of a password.
Other options:
* A. MaxSessions controls the number of simultaneous SSH sessions but is not causing the login denial here.
* B. PAM (Pluggable Authentication Modules) is disabled, but enabling it is not required for basic SSH authentication.
* C. Changing the SSH port is unrelated to the authentication method issue.
Reference:
CompTIA Linux+ Study Guide: Exam XK0-005, Sybex, Chapter 11: "Securing Linux", Section: "Securing SSH Access" CompTIA Linux+ XK0-005 Objectives, Domain 3.0: Security

To unlock an account that has been locked due to login failures, the administrator can use the command pam_tally2 --user=dev2 --reset (D). This will reset the failure counter for the user
"dev2" and allow the user to log in again.

Explanation
The user has the wrong shell assigned to the account, which is causing the issue. The output 1 shows that the user's shell is set to /bin/false, which is not a valid shell and will prevent the user from logging in. The output
2 shows that the user's home directory has the correct permissions (drwxr-xr-x), and the output 3 shows that the user entered the correct password and was accepted by the SSH daemon, but the session was closed immediately due to the invalid shell. The other options are incorrect because they are not supported by the outputs. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 13: Managing Network Services, page 413.