Dr Patel is already uniquely identified. Choose the standard sentence that adds her role as extra information.
Dr Patel, who chairs the panel, arrived early.✓Richtige Antwort
Dr Patel who chairs the panel arrived early.
Dr Patel, that chairs the panel, arrived early.
Dr Patel, who chairs the panel arrived early.
Erklärung
The clause about chairing the panel is non-defining, so it is enclosed by commas and uses who for a person. The version with that is the closest distractor, but that cannot introduce a non-defining relative clause.