【单选题】
Study the information and the relevant configuration file below for the Testking Branch router<img src="https://nimg.ppkao.com/2018-07/longzhengxuan/201807301032157546.jpg?sign=cd6279140029092513e79dee14f13f44&t=62d4357a" /><br /> What additional command must be executed on the Branch router before interesting traffic will initiate an ISDN call?()
A、(config-if)# dialer-group 1
B、(config-if)# dialer-list 1
C、(config-if)# dialer map 1
D、(config-if)# dialer-route 1