Explanation
Explanation:
Volume storage is allocated via a LUN to a system and then treated the same as any traditional storage. The operating system is responsible for formatting and securing volume storage as well as controlling all access to it. Applications, although they may use volume storage and have permissions to write to it, are not responsible for its formatting and security. Both a hypervisor and the management plane are outside of an individual system and are not responsible for managing the files and storage within that system.

Cloud services make exclusive use of virtualization, and systems change over time, including the addition, subtraction, and reimaging of virtual machines. It is extremely unlikely that the exact same virtual machines and images used in a previous audit would still be in use or even available for a later audit, making the tracking of changes over time extremely difficult, or even impossible.
Elasticity refers to the ability to add and remove resources from a system or service to meet current demand, and although it plays a factor in making the tracking of virtual machines very difficult over time, it is not the best answer in this case.
Resource pooling pertains to a cloud environment sharing a large amount of resources between different customers and services. Portability refers to the ability to move systems or services easily between different cloud providers.

Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.