In Kubernetes, the simplest and most direct way to create a Pod that runs a single container is to use the kubectl run command with the appropriate image specification. The command kubectl run my-app --image=nginx explicitly instructs Kubernetes to create a Pod named my-app using the nginx container image, which makes option B the correct answer.

The kubectl run command is designed to quickly create and run a Pod (or, in some contexts, a higher-level workload resource) from the command line. When no additional flags such as --restart=Always are specified, Kubernetes creates a standalone Pod by default. This is ideal for simple use cases like testing, demonstrations, or learning scenarios where only a single container is required.

Option A is incorrect because kubectl create nginx --name=my-app is not valid syntax; the create subcommand requires a resource type (such as pod, deployment, or service) or a manifest file. Option C is also incorrect because kubectl create my-app --image=nginx omits the resource type and therefore is not a valid kubectl create command. Option D is incorrect because kubectl run nginx --name=my-app attempts to use the deprecated --name flag, which is no longer supported in modern versions of kubectl.

Using kubectl run with explicit naming and image flags is consistent with Kubernetes command-line conventions and is widely documented as the correct approach for creating simple Pods. The resulting Pod can be verified using commands such as kubectl get pods and kubectl describe pod my-app.

In summary, Option B is the correct and verified answer because it uses valid kubectl syntax to create a Pod named my-app running the nginx container image in a straightforward and predictable way.