A client wishes to upload and download a few files from the network server. The client wants to upload some of the files to a website. Which ports would establish an active connection? (Select all that apply.)a.TCP/80b.TCP/443c.TCP/21d.TCP/20

The ports that would establish an active connection for uploading and downloading files from a network server and uploading files to a website are:

a. TCP/80 - This is the default port for HTTP (Hypertext Transfer Protocol), which is used for transferring files over the internet. It is commonly used for web browsing, so it would be used for uploading files to a website.

b. TCP/443 - This is the default port for HTTPS (HTTP Secure), which is a secure version of HTTP. It is used for secure web browsing and secure file transfer, so it would also be used for uploading files to a website.

c. TCP/21 - This is the default port for FTP (File Transfer Protocol), which is used for transferring files between a client and a server on a network. It would be used for uploading and downloading files from a network server.

d. TCP/20 - This is also associated with FTP for data transfer. However, it's not typically used to establish connections but rather for the actual data transfer once the connection has been established on port 21. So, it's not typically used to establish an active connection.

So, the correct answers are a. TCP/80, b. TCP/443, and c. TCP/21.