When can the clinical trial close out visit be done?

A$.$ When the monitor has received the confirmation of the REC$$s notification from the Principal Investigator that the trial is completed

B$.$ When the monitor has reviewed both the sponsor and the investigational site files for completeness

C$.$ When the Investigator has returned all unused IMP and other clinical trial materials and has informed the REC

D$.$ Just after the last visit of the last patient, if the case report form has been completed