In a service mesh architecture, service proxies (such as Envoy, Linkerd proxy, or Istio sidecar) are deployed alongside each service instance to handle communication between services. The control plane consists of various components responsible for configuring, managing, and monitoring the behavior of the service proxies, including features like traffic routing, load balancing, encryption, authentication, and observability. Together, these components enable advanced traffic management, security, and observability capabilities in a distributed microservices environment.

I can confirn that D is the corrct answer, anyway the question is a bit tricky, because the data plan can be considered as the set of service proxies so even the C answer could be considered