A web server that provides shopping cart capabilities for external end users will likely function with which of the following protocols?

HTTPS (HTTP Secure) combines HTTP with TLS/SSL encryption to provide secure, authenticated communication between a web server and browser. An e-commerce shopping cart handles sensitive data such as credentials and payment information, making HTTPS the required protocol for both security and regulatory compliance (e.g., PCI-DSS).

POP3 (Post Office Protocol 3) is an email retrieval protocol used by mail clients to download messages from a mail server, unrelated to web applications.

SSH (Secure Shell) provides encrypted remote command-line access to systems and is not a protocol for serving web content to end users.

SMTP (Simple Mail Transfer Protocol) is used to send email between mail servers and is not used for web-based shopping or browsing.