The correct answer is A pod contains one or more containers that share the same network namespace storage and IP and are scheduled together.

This is correct because a pod is the smallest deployable unit in Kubernetes and it groups one or more containers that are colocated and scheduled onto the same node. Containers in the same pod share the pod network namespace so they share the same IP address and can communicate over localhost, and they can also share storage volumes that are mounted into the pod.

Containers are independently scheduled and run beside pods on each node is wrong because scheduling happens at the pod level and containers run inside pods rather than running independently beside them.

A controller specification runs within a container which in turn executes inside a pod is wrong because a controller specification is an API object in the control plane and does not itself run inside a container. Controller logic is implemented by controller processes that may run in the control plane or as controller pods, but the spec is an object not an executable container image.

Controllers such as ReplicaSet or Deployment define pods which then encapsulate one or more containers is misleading and marked incorrect here because controllers define pod templates and manage creation of pod replicas rather than directly being the pod. The essential architectural relationship the exam expects is that pods encapsulate containers and are the schedulable unit.

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