Reversibility is the ability for a cloud customer to easily remove their applications or data from a cloud environment, as well as to ensure that all traces of their applications or data have been securely removed per a predefined agreement with the cloud provider.

Explanation
Simple Object Access Protocol (SOAP) and Representational State Transfer (REST) are the most commonly used APIs within a cloud environment. Extensible Markup Language (XML) and Security Assertion Markup Language (SAML) are both standards for exchanging encoded data between two parties, with XML being for more general use and SAML focused on authentication and authorization data.

Explanation/Reference:
Explanation:
DNSSEC does not require any additional DNS queries to be performed. The DNSSEC integrity checks and validations are all performed as part of the single DNS lookup resolution.