![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
One cannot notice if the landline is being used by others because
A.
the ooma traffic cannot be calculated by the outside network.
B.
your monthly phone bill still remains stable with new traffic.
C.
your Hub will dial the target number from a second Hub.
D.
the whole system keeps going with the broadband connection.