Which statement correctly describes the implementation of Availability Zones in Azure?

The statement indicating that "None of the above" is correct because it reflects the reality of how Azure implements Availability Zones. Azure does indeed support Availability Zones in multiple regions across the globe, but it does not automatically implement them by default for all resources. Instead, customers must explicitly choose to deploy resources within Availability Zones when configuring their services, depending on their needs for high availability and redundancy.

Moreover, while it is true that not all Azure regions have Availability Zones, the assertion that Azure only supports Availability Zones in certain regions is overly simplistic and does not provide a complete picture. Availability Zones are an essential aspect of Azure's architecture, designed to enhance uptime by spreading resources across physically separated datacenters within a region. Therefore, the most accurate choice reflects that the previous statements do not fully encompass how Azure Availability Zones function.