The correct option is C. SFTP. Detailed Explanation 1. Understanding the Protocols: - FTP (File Transfer Protocol): This is a standard network protocol used to transfer files from one host to another over a TCP-based network. However, FTP does not encrypt its traffic, which means that data, including usernames and passwords, can be intercepted by malicious actors.

• HTTP (Hypertext Transfer Protocol): This is the foundation of data communication on the World Wide Web. While it is used for transferring web pages and other resources, it does not provide any security features. Data sent over HTTP can be intercepted and read by anyone who has access to the network.
• SFTP (SSH File Transfer Protocol): This protocol is a secure version of FTP that uses the Secure Shell (SSH) protocol to encrypt the data being transferred. This means that both the commands and the data are encrypted, making it much more secure than FTP. SFTP is specifically designed for secure file transfer.
• SMTP (Simple Mail Transfer Protocol): This protocol is used for sending emails. While it is essential for email communication, it is not used for file transfers.

2. Why SFTP is the Correct Answer: - Security: SFTP encrypts both the data and the commands, ensuring that sensitive information is protected during transmission. This is crucial for maintaining confidentiality and integrity, especially when transferring sensitive files over the Internet. - Authentication: SFTP uses SSH for authentication, which can include password-based or key-based authentication methods. This adds an additional layer of security compared to FTP. - Data Integrity: SFTP ensures that the data sent and received is not tampered with during transmission, providing a reliable way to transfer files securely. 3. Why the Other Options are Incorrect: - A. FTP: As mentioned, FTP does not provide any encryption, making it unsuitable for secure file transfers. It is vulnerable to eavesdropping and man-in-the-middle attacks. - B. HTTP: While HTTP is widely used for web traffic, it does not secure the data being transferred. For secure web traffic, HTTPS (HTTP Secure) is used, which is not the same as SFTP. - D. SMTP: This protocol is not designed for file transfers at all; it is specifically for sending emails. While it can attach files to emails, it does not facilitate direct file transfers like SFTP does. Summary of Key Points

• SFTP is the secure protocol for transferring files over the Internet, utilizing SSH for encryption and authentication.
• FTP and HTTP lack security features, making them unsuitable for sensitive data transfers.
• SMTP is unrelated to file transfers, focusing instead on email communication.
• Always choose protocols that ensure data security, especially when handling sensitive information.

Revision Summary

• SFTP is the secure file transfer protocol that encrypts data.
• FTP and HTTP do not provide security, making them vulnerable.
• SMTP is for email, not file transfers.
• Always prioritize security in data transmission protocols.