The correct answer is: A. unmanaged storage is reliable.
Unmanaged storage is not reliable because it is not managed by a third-party provider. This means that the user is responsible for all aspects of the storage, including backups, security, and maintenance. If something goes wrong with the storage, the user is responsible for fixing it.
Managed storage is reliable because it is managed by a third-party provider. This means that the provider is responsible for all aspects of the storage, including backups, security, and maintenance. If something goes wrong with the storage, the provider is responsible for fixing it.
Most of the user-based applications that work with cloud storage are of managed type. This is because managed storage is more reliable and easier to use than unmanaged storage.
Therefore, the correct answer is: A. unmanaged storage is reliable.