Which of the following is a valid XML root expression when using DataWeave 1.0 with output application/xml?

• A. user: { fname: "John", lname: "Doe" }
• B. { fname: "John", lname: "Doe" }
• C. { "fname": "John", "lname": "Doe" }
• D. <user><fname>John</fname><lname>Doe</lname></user>

Answer: (A)

DataWeave 1.0 XML output requires a single root element, defined by the top-level key followed by a colon and a map of its children. The structure rootName: { ... } tells DataWeave to create an XML document with a root element named rootName, whose child elements come from the keys inside the nested map. In this example, using user as the root yields a single element containing John and Doe, which is a valid XML with one root.

The other forms would not produce a single root element. If you had multiple top-level keys, you’d end up with multiple root elements, which XML does not allow. A literal XML string shown is not the DW root expression that generates XML from a data structure.