VOLTE视频起呼,被叫音频应答后,SBC发送()消息至PCRF,指示REMOVE VIDEO

VOLTE视频起呼,被叫音频应答后,SBC发送()消息至PCRF,指示REMOVE VIDEO

A.UDR

B.AAR

C.LIR

D.UDA

正确答案是B