Which of the following ports and protocol types must be opened on a host with a host-based firewall to allow
incoming SFTP connections?

A.
21/UDP

B.
21/TCP

C.
22/UDP

D.
22/TCP

Explanation:
SSH uses TCP port 22. All protocols encrypted by SSH, including SFTP, SHTTP, SCP, SExec, and slogin, also
use TCP port 22.