Which is false about HTTP?

HTTP (Hypertext Transfer Protocol) is an application-layer protocol defined by IETF RFC 9110. It is a stateless request–response protocol between a client and a server, and an HTTP session consists of one or more such request–response transactions. By IANA's port assignment, plain HTTP's default port is 80, while port 443 is the default for the separate HTTPS scheme (HTTP layered over TLS/SSL).

Checking each option against this definition:

• “It is an application level protocol” matches HTTP's RFC 9110 classification as an application-layer protocol — true, not the false statement.

• “HTTP is the foundation of data communication for the World Wide Web, where hypertext documents include hyperlinks to other resources” matches HTTP's founding purpose — true, not the false statement.

• “HTTP functions as a request–response protocol in the client–server computing model” matches the standard specification of HTTP's behaviour — true, not the false statement.

• “An HTTP session is a sequence of network request–response transactions” matches the standard definition of an HTTP session — true, not the false statement.

• “HTTP's default port number is 443” contradicts the IANA-assigned default: HTTP's default port is 80; port 443 is the default for the separate HTTPS scheme — this is the false statement.

Cross-checking against IANA's service-name/port registry confirms port 80 is the default for HTTP and port 443 is the default for HTTPS, so the statement claiming 443 as HTTP's default port is the one false statement among those given.