Which of the following best describes a headless service in Kubernetes?

• A. It uses a load balancer to distribute traffic
• B. It has no cluster IP, allowing direct pod DNS resolution
• C. It requires an external DNS
• D. It is only accessible within the cluster

Answer: (B)

A headless service is defined by not getting a cluster IP. When you create such a service (clusterIP is None), there isn’t a single virtual IP to front the pods. Instead, the service’s DNS name resolves to the actual pods backing it, so clients can reach the individual pod IPs directly through DNS, or use SRV records to discover the ports. This is why the description “no cluster IP, allowing direct pod DNS resolution” best captures headless services.

That’s why the other statements don’t fit: there isn’t a service-level load balancer for traffic distribution, since there’s no cluster IP to balance to; internal DNS is sufficient for DNS resolution—external DNS isn’t a requirement; and while headless services are often used within the cluster, they aren’t defined by being strictly inaccessible from outside the cluster.