The correct option is C. SSH. Detailed Explanation 1. Understanding SSH: - SSH (Secure Shell) is a protocol used to securely access and manage devices over an unsecured network. It encrypts the data transmitted between the client and the server, ensuring that sensitive information such as passwords and commands cannot be intercepted by malicious actors. - SSH is commonly used for remote login to servers, secure file transfers, and executing commands on remote machines. 2. Why SSH is the Correct Answer: - Security Features: SSH provides strong authentication and secure encrypted communications. This means that even if someone tries to eavesdrop on the connection, they would not be able to read the data being transmitted. - Use Cases: It is widely used by system administrators and developers to manage servers and applications securely, making it a go-to protocol for secure data transmission over the internet. Analysis of Other Options A. FTP (File Transfer Protocol): - Explanation: FTP is used for transferring files between a client and a server. However, it does not provide any encryption, meaning that data, including usernames and passwords, is sent in plain text. - Weakness: Because of its lack of security, FTP is not suitable for transmitting sensitive data over the internet. B. HTTP (Hypertext Transfer Protocol): - Explanation: HTTP is the foundation of data communication on the web. It is used for transferring web pages and other resources. However, like FTP, HTTP does not encrypt data, making it vulnerable to interception. - Weakness: While HTTP is essential for web browsing, it does not provide the security needed for transmitting sensitive information. This is why HTTPS (HTTP Secure) was developed, which uses SSL/TLS to encrypt the data. D. SMTP (Simple Mail Transfer Protocol): - Explanation: SMTP is used for sending emails. While it is essential for email communication, it does not inherently provide encryption for the data being transmitted. - Weakness: Although there are extensions to SMTP that allow for secure email transmission (like STARTTLS), the basic SMTP protocol does not secure the data, making it less suitable for secure data transmission compared to SSH. Summary of Key Points

• SSH is the best choice for securely transmitting data over the internet due to its strong encryption and authentication features.
• FTP and HTTP do not provide security, making them unsuitable for sensitive data transmission.
• SMTP is primarily for email and lacks inherent security features, although it can be secured with additional protocols.
• Always choose protocols that provide encryption and security when transmitting sensitive information over the internet.

Revision Summary

• SSH is the protocol for secure data transmission over the internet.
• FTP and HTTP lack encryption, making them insecure for sensitive data.
• SMTP is for email and does not provide inherent security.
• Always prioritize security features when selecting communication protocols.