A Kubernetes Deployment is a controller that manages the lifecycle of pods. Its primary function, as defined by the replicas field in its specification, is to ensure that a specified number of pod replicas are running and available. It continuously monitors the state of its pods and automatically replaces any that fail, are terminated, or become unresponsive, thereby guaranteeing the desired state. The containerPort field within the pod template is a declarative way to specify the network port on which a container will listen for traffic. While this field is informational, it correctly documents the port the container exposes.

B. The Deployment's name is explicitly defined as nginx-deployment in the metadata.name field of the YAML, not nginx.

C. The Deployment creates pods with unique, auto-generated names based on the ReplicaSet hash (e.g., nginx-deployment-5c689d88bb-h9k7l), not a static name like nginx.

E. The kubectl create command only submits the object definition to the API server. The command succeeds if the YAML is valid. An unavailable image causes a pod to fail later during the scheduling/pulling phase, not the initial Deployment creation.

1. Kubernetes Documentation

"Deployments": A Deployment's primary purpose is to provide declarative updates for Pods and ReplicaSets. "You describe a desired state in a Deployment

and the Deployment Controller changes the actual state to the desired state at a controlled rate." This supports option A's statement about guaranteeing a number of pods.

Source: kubernetes.io/docs/concepts/workloads/controllers/deployment/

Section: "What is a Deployment?".

2. Kubernetes Documentation

"Container v1 core" API Reference: The containerPort field is officially defined as the "Number of port to expose on the pod's IP address. This must be a valid port number

0 < x < 65536." This confirms the purpose described in option D.

Source: kubernetes.io/docs/reference/generated/kubernetes-api/v1.28/

Section: "Container v1 core".

3. Kubernetes Documentation

"Object Names and IDs": "Each object in your cluster has a Name that is unique for that type of resource." The YAML clearly specifies name: nginx-deployment

making option B incorrect. The document also explains that pods owned by a ReplicaSet have unique

generated names

making option C incorrect.

Source: kubernetes.io/docs/concepts/overview/working-with-objects/names/

Section: "Names".

4. Kubernetes Documentation

"Container Images": The process of pulling an image is handled by the kubelet on a node after a pod has been scheduled. If an image cannot be pulled

the pod enters a failure state like ImagePullBackOff. The initial kubectl create command

which creates the Deployment object

would have already succeeded. This invalidates the premise of option E.

Source: kubernetes.io/docs/concepts/containers/images/

Section: "Image pull policy".