Final answer:
The triage nurse should first verify the advance directive's placement in the chart and, if present and valid, follow the client's DNR wishes by stopping the code.
Step-by-step explanation:
The appropriate response from the triage nurse in this situation is to first verify the advance directive's placement in the chart. It is important to confirm the presence and validity of the DNR order before taking any further actions. This ensures that the client's wishes are respected and medical interventions are in accordance with their wishes. Once the advance directive is confirmed, the code team should follow the client's DNR wishes by stopping the code.