Which URL is necessary for enabling data write from the VM to the cache storage account in the source region?

The correct choice for enabling data write from the virtual machine (VM) to the cache storage account in the source region is the URL associated with Blob storage, which is *.blob.core.windows.net.

This URL specifically pertains to Azure Blob Storage, which is the service used for storing large amounts of unstructured data, such as text or binary data, and is crucial for operations that require storing or writing data. When applications running on a VM need to perform actions like saving data or files to a storage account, they interact directly with the Blob Storage service.

In the context of cache storage, the write operations involve uploading data to this service, and thus it is essential that the correct URL pattern is used. Accessing this specific URL allows the VM to authenticate and communicate accordingly with the Blob service in the Azure cloud, facilitating successful data operations.

Other options represent different Azure services or endpoints that do not relate to write operations to Blob storage. This is why they are not suitable for the task of writing data from the VM to the storage account in this context.