How many discrete call legs are needed to set up a call between the POTS phone attached to TEST-Router 1 and the phone in the PSTN?

You are CCNA VOICE associate in Certkey.com. How many discrete call legs are needed to set up a call between the POTS phone attached to TEST-Router 1 and the phone in the PSTN?

A.
3

B.
4

C.
6

D.
7