Data that falls under the purview of an eDiscovery request is that which is in the possession, custody, or control of the organization. Although this is an easy concept in a traditional data center, it can be difficult to distinguish who actually possesses and controls the data in a cloud environment due to multitenancy and resource pooling. Although these options provide similar- sounding terms, they are ultimately incorrect.

Tokenization is the practice of utilizing a random and opaque "token" value in data to replace what otherwise would be a sensitive or protected data object. The token value is usually generated by the application with a means to map it back to the actual real value, and then the token value is placed in the data set with the same formatting and requirements of the actual real value so that the application can continue to function without different modifications or code changes.

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.

Simple Object Access Protocol (SOAP) encapsulates its information in what is known as a SOAP envelope. It then leverages common communications protocols for transmission. Object is a type of cloud storage, but also a commonly used term with certain types of programming languages.
Packet and payload are terms that sound similar to envelope but are not correct in this case.