The correct answer is B.
OBJ-1.2: A swagger document is the REST API equivalent of a WSDL document that defines a SOAP-based web service. Since Dion Training’s voucher fulfillment system uses a REST API, you should request a copy of the swagger document to conduct a more efficient assessment of their web application since this is a known-environment assessment. SDK documentation is used to document the software development kit and is not relevant to the REST API being tested. An XML Schema Definition (XSD) is a recommendation that enables developers to define the structure and data types for XML documents.