Which of the following encryption options establishes an encrypted link between a web server and a browser and ensures privacy and integrity of data on that link?

The correct answer is Secure Socket Layer (SSL), which is designed specifically to create a secure encrypted link between a web server and a web browser. SSL operates at the transport layer of the networking model and provides a secure channel over an insecure network, ensuring that the data transmitted remains private and protected from eavesdropping or tampering.

By establishing this encrypted connection, SSL serves two critical functions: it ensures the privacy of the data being transmitted by encrypting the information, making it unreadable to anyone who might intercept it, and it maintains the integrity of the data, preventing modifications from being made during transit. This is particularly vital for transactions involving sensitive information, such as credit card numbers and personal details, where both privacy and integrity are essential.

Other options do have roles in network security but do not specifically establish an encrypted link between a web server and a browser in the same way that SSL does. For example, secure shell is more focused on secure remote login sessions, a virtual private network secures communication across a broader network, and IPsec is used for securing Internet Protocol communications but does not directly relate to web browser communications. Thus, SSL is uniquely suited for web traffic encryption, providing the necessary protection for data exchanged over the internet.