Choose the ports that are used to access the FTP (File Transfer Protocol) protocol.

A.
Ports 20 and 21.

B.
Ports 80 and 443.

C.
Ports 20 and 80.

D.
Ports 21 and 23.

Explanation:

In basic FTP operations, port 20 is the data port and port 21 is the command port.