CMDB Query Builder provides purpose-built Export Query and Import Query functions for transferring saved query definitions between ServiceNow instances. The administrator selects the saved query, exports its definition as an XML file, and the receiving team imports that file using the Import Query function. The imported definition then appears in the destination instance's Saved Queries tab.

Exporting the query as a report would transfer report configuration rather than the complete Query Builder canvas and relationship definition. A generic record-level XML export is not the prescribed Query Builder workflow.

ServiceNow also documents transfer through an update set, but identifies that process as an alternative maintained for backward compatibility. Because the question asks for the direct and recommended Query Builder approach, Option A is the best answer.