In which step of the 'incident handling and resolution' process does the service desk agent...

In theincident handling and resolutionprocess, the service desk agent confirms that a user query refers to an incident during theincident detectionstep. This step involves recognizing that an issue reported by a user is indeed an incident that requires further investigation and classification​​.

Incident classification(Option A) happens after detection and involves categorizing the incident.

Incident registration(Option C) involves logging the incident once it is confirmed.

Incident diagnosis(Option D) occurs later, during the troubleshooting phase.