CompTIA Exam Questions

Which of the following firewall ports must be opened to…

A company has decided to upgrade its legacy phone system to VoIP. The new phones will download the configurations from a TFTP server each time they boot up.
Which of the following firewall ports must be opened to ensure the phones can communicate with the server?

A.
20

B.
53

C.
69

D.
161

Explanation:
https://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocol