This is the least offensive response.
Choice D is incorrect is because although true EDs triage based on severity, telling the patient (especially since she's angry) this could offend her by suggesting their reason for the ED visit is considered "not important".
submitted by โfreemanpeng(7)
FA2021 p276 "Thank the patient for being patient and apologize for any inconvenience. Stay away from efforts to explain the delay." So it's another ugly FA-copying Qs