路由器S0/0 接口通过帧中继接入网络，在此路由器上看到如下接口信息：
[MSR] display interface Serial 0/0
Serial0/0 current state: UP
Line protocol current state: UP
Internet Address is 3.3.3.1/24 Primary
Link layer protocol is FR IETF
LMI DLCI is 0, LMI type is Q.933a, frame relay DTE
LMI status enquiry sent 91, LMI status received 69
LMI status timeout 22, LMI message discarded 1
那么可知_（ ）_。
A.接口封装的LMI 类型是Q.933a B.接口使用虚电路号是DLCI 0 C.接口的PVC 状态已经是UP D.本接口已经发送了91 个状态查询报文来查询接口的PVC 状态正确答案AD
