Explanation
This command will ensure that overlay traffic between service tasks is encrypted, because it uses the -o encrypted=true option to enable encryption for the overlay network. According to the official documentation, when you enable overlay encryption, Docker creates IPSEC tunnels between all the nodes where tasks are scheduled for services attached to the overlay network. These tunnels also use the AES algorithm in GCM mode and manager nodes automatically rotate the keys every 12 hours.
References: https://docs.docker.com/network/drivers/overlay/#encryption
https://docs.docker.com/network/network-tutorial-overlay/#use-an-overlay-network-for-standalone-containers

Explanation
Optimizing images by copying artifacts selectively from previous stages is an advantage of multi-stage builds.
Multi-stage builds allow you to use multiple FROM statements in your Dockerfile, each starting a new stage of the build. You can selectively copy artifacts from one stage to another, leaving behind everything you don't want in the final image. This reduces the size and complexity of your images, and improves security and performance. References: https://docs.docker.com/build/building/multi-stage/,
https://docs.docker.com/engine/reference/builder/#copy

Explanation
This command will not mount the host's '/data' directory to the ubuntu container in read-only mode, because it has several syntax errors and missing options. According to the official documentation, the correct command should be:
docker run --volume /data:/mydata:ro --read-only ubuntu
The errors and missing options are:
The --add-volume flag does not exist and should be replaced by --volume or -v to mount a host directory as a data volume.
The --volume flag requires a colon (:) to separate the host directory and the container directory, not a space.
The --read-only flag applies to the whole container's file system, not just the mounted volume. To make the volume read-only, a :ro suffix should be added to the --volume flag.
The ubuntu image name should be the last argument of the command.
References: https://docs.docker.com/engine/reference/commandline/run/#mount-volume-v-read-only
https://docs.docker.com/storage/volumes/#use-a-read-only-volume

Explanation
The controller managing the pod is not autoscaled back to delete the unhealthy pod and alleviate load, because this is not how Kubernetes handles pod failures. According to the official documentation, Kubernetes will try to maintain the desired number of pods for each controller, and will not scale down or up based on pod health.
References:
https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller/#how-a-replicationcontroller-wor

Explanation
Environment variables cannot be used to schedule containers to meet the security policy requirements.
Environment variables are key-value pairs that can be passed to containers when they are created or run.
Environment variables can be used to configure the behavior of the containerized application or provide runtime information, such as database credentials, API keys, etc. Environment variables do not affect how containers are scheduled on nodes in a swarm mode cluster. References:
https://docs.docker.com/engine/reference/commandline/run/#set-environment-variables-e-env-env-file,
https://docs.docker.com/engine/swarm/services/#create-a-service