Final answer:
The end of a closed-loop referral process would be when the specialist conducts the sleep study and communicates the results and recommendation to the patient.
Step-by-step explanation:
The END of a closed-loop referral process would be option (C) The specialist conducts the sleep study, and communicates the results and recommendation to the patient.
In a closed-loop referral process, the primary care provider (PCP) starts by referring the patient to a specialist for further evaluation or treatment. The PCP communicates the referral to the specialist (option A), and the patient then makes an appointment with the specialist (option B). The final step is when the specialist conducts the sleep study and shares the results and recommendations with the patient, which marks the end of the closed-loop referral process.