The correct command to get field-level schema information about spec.replicas in a Deployment is kubectl explain deployment.spec.replicas, so B is correct. kubectl explain is designed to retrieve documentation for resource fields directly from Kubernetes API discovery and OpenAPI schemas. When you use kubectl explain deployment.spec.replicas, kubectl shows what the field means, its type, and any relevant notes—exactly what “provides information about the field” implies.
This differs from kubectl get and kubectl describe. kubectl get is for retrieving actual objects or listing resources; it does not accept dot-paths like deployment.spec.replicas as a normal resource argument. You can use JSONPath/custom-columns with kubectl get deployment -o jsonpath='{.spec.replicas}' to extract the live value, but that’s not what option A shows, and it’s not “documentation.” kubectl describe provides a human-friendly summary of a live resource instance (events, status, spec), but it doesn’t target schema field definitions via dot-path in the way shown in option C.
Option D is not valid syntax: kubectl explain deployment --spec.replicas is not how kubectl explain accepts nested field references. The correct pattern is positional dot notation: kubectl explain ......
Understanding spec.replicas matters operationally: it defines the desired number of Pod replicas for a Deployment. The Deployment controller ensures that the corresponding ReplicaSet maintains that count, supporting self-healing if Pods fail. While autoscalers can adjust replicas automatically, the field remains the primary declarative knob. The question is specifically about finding information (schema docs) for that field, which is why kubectl explain deployment.spec.replicas is the verified correct answer.
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