Option D is the most appropriate choice for this scenario. Amazon EKS is a fully managed Kubernetes service that can handle large-scale data processing tasks with high availability and fault tolerance. When ensuring high availability and fault tolerance, consider the choice of Kubernetes node types, which determine the CPU and memory resources available to the containers. Additionally, the number of nodes in the cluster should be chosen based on the workload requirements to ensure sufficient resources for processing tasks. To achieve high availability and fault tolerance, you can leverage Kubernetes features such as self-healing, which automatically replaces failed nodes or pods, horizontal pod autoscaling, which adjusts the number of pods based on resource utilization, and pod disruption budgets, which ensure a minimum number of pods are available during voluntary disruptions. You can also use Amazon EKS' managed node groups and Fargate to simplify cluster management and improve fault tolerance.