Object storage is typically used to house virtual machine images because it is independent from other systems and is focused solely on storage. It is also the most appropriate for handling large individual files.
Volume storage, because it is allocated to a specific host, would not be appropriate for the storing of virtual images. Structured and unstructured are storage types specific to PaaS and would not be used for storing items used throughout a cloud environment.

Explanation
The EU passed Directive 95/46 EC in 1995, which established data privacy as a human right. The other years listed are incorrect.