When using multiple configurations of the same Terraform provider, what meta-argument must be included in any non-default provider configurations?

`name` is not a standard meta-argument used to differentiate provider configurations; provider types are implicitly named by their type (e.g., `aws`, `azurerm`).

The `alias` meta-argument is essential for distinguishing between multiple configurations of the same provider type within a single Terraform configuration. Each non-default provider block must have a unique alias, allowing resources or modules to explicitly specify which provider configuration to use.

`depends_on` is used to manage explicit dependencies between resources or modules, not to differentiate multiple provider configurations.

`id` is typically an attribute of a specific resource instance, not a meta-argument for provider configuration blocks.