Measured service is the aspect of cloud computing that pertains to cloud services and resources being billed in a metered way, based only on the level of consumption and duration of the cloud customer.
Although they sound similar to the correct answer, none of the other choices is the actual cloud terminology.

Explanation/Reference:
Explanation:
Federation is not a component of access control. Instead, it is used to allow users possessing credentials from other authorities and systems to access services outside of their domain. This allows for access and trust without the need to create additional, local credentials. Access control encompasses not only the key concepts of authorization and authentication, but also accounting. Accounting consists of collecting and maintaining logs for both authentication and authorization for operational and regulatory requirements.

Explanation
Cryptographic keys should not be stored along with the data they secure, regardless of key length. We don't split crypto keys or generate redundant keys (doing so would violate the principle of secrecy necessary for keys to serve their purpose).

Explanation
The locality--or physical location and jurisdiction where the system or data resides--is the dominant driver of regulations. This may be based on the type of data contained within the application or the way in which the data is used. The contract and SLA both articulate requirements for regulatory compliance and the responsibilities for the cloud provider and cloud customer, but neither artifact defines the actual requirements.
Instead, the contract and SLA merely form the official documentation between the cloud provider and cloud customer. The source of the data may place contractual requirements or best practice guidelines on its usage, but ultimately jurisdiction has legal force and greater authority.