What is the command sequence to configure an FXS port as a signal loop-start?
A.
router(config)# voice-port slot/port
router(config-voiceport)# signal loopstart
router(config-voiceport)# shutdown
router(config-voiceport)# no shutdown
B.
router(config)# voice-port slot/port
router(config-voiceport)# signal loopstart
C.
router(config)# voice-port slot/port
router(config-voiceport)# signal groundstart
router(config-voiceport)# shutdown
router(config-voiceport)# no shutdown
D.
router(config)# voice-port slot/port
router(config-voiceport)# signal groundstart