Correct Answer: C
Store your container images in Azure Container Registry and geo-replicate the registry to each AKS region.
To deploy and run your applications in AKS, you need a way to store and pull the container images. Container Registry integrates with AKS, so it can securely store your container images or Helm charts. Container Registry supports multi-master geo-replication to automatically replicate your images to Azure regions around the world.
To improve performance and availability, use Container Registry geo-replication to create a registry in each region where you have an AKS cluster. Each AKS cluster then pulls container images from the local container registry in the same region:
Geo-replication is a feature of Premium SKU container registries
Incorrect Answers:
A. Azure Cache for Redis
Azure Cache for Redis provides an in-memory data store based on the Redis software. This is not used as to store container images.
B. Azure Content Delivery Network (CDN)
A content delivery network (CDN) is a distributed network of servers that can efficiently deliver web content to users. CDNs' store cached content on edge servers in point-of-presence (POP) locations that are close to end users, to minimize latency. This is not used as to store container images.
D. geo-redundant storage (GRS) accounts
GRS Storage accounts are used to store data in secondary region for high durability. The data in the secondary region isn't available for read or write access unless there is a failover to the secondary region.
Reference:
https://docs.microsoft.com/en-us/azure/aks/operator-best-practices-multi-region#enable-geo-replication-for-container-images