E is the correct answer because access to resources in Azure is dealt with through Azure Role-Based Access Control (RBAC). This allows fine-grained access management for Azure. System-assigned managed identities can be assigned roles through IAM settings of a resource, granting them permissions to perform certain actions.

To access files in Azure Storage, you would assign the Storage Blob Data Reader role for read access and the Storage Blob Data Contributor role for write access to the managed identity in the IAM settings.

Here's the Microsoft documentation needed about granting access using RBAC and Azure AD identities: https://docs.microsoft.com/en-us/azure/role-based-access-control/role-assignments-portal