Following the migration of a monolithic application to a microservices architecture on GCP, which combination of services should be employed to ensure high availability, fault tolerance, and the facilitation of canary deployments?

*Explanation: Kubernetes Engine combined with Istio and Traffic Director is the most effective solution for ensuring high availability, fault tolerance, and enabling canary deployments in a microservices architecture. Kubernetes Engine provides a managed environment for deploying containerized applications, which is crucial for a microservices setup. Istio enhances this by offering advanced traffic management capabilities, including canary deployments, allowing for gradual rollouts and efficient routing. Traffic Director further augments this setup by offering global load balancing, which is key for high availability and fault tolerance. The other service combinations, while useful in specific contexts, do not collectively offer the same level of support for high availability, fault tolerance, and canary deployments as does the Kubernetes-Istio-Traffic Director trio.*