Which of the following is an example of a common method of establishing secure communication over a network?

FTPS, or File Transfer Protocol Secure, is a common method of establishing secure communication over a network. It enhances the standard FTP protocol by adding a layer of security through the use of SSL/TLS encryption. This ensures that any data transferred between the client and server is encrypted, which protects sensitive information from eavesdroppers and man-in-the-middle attacks.

In contrast, HTTP does not provide encryption and thus is not considered secure for transmitting confidential data. Telnet is also an insecure protocol, as it transmits data, including passwords, in plaintext. Similarly, FTP lacks built-in security measures, exposing data to potential interception by unauthorized entities. Therefore, FTPS stands out as a stronger choice for secure data transmission compared to the other options provided.