Essential services provided by a network, such as secure web browsing and file transfer?

• A. Speed considerations
• B. Interference and attenuation factors
• C. Ports
• D. Basic network services

Answer: (D)

Essentials are the standard services a network provides to enable communication between devices. Basic network services is the best fit because it describes the common functions a network delivers for users, such as secure web browsing (HTTPS) and file transfer (FTP/FTPS/SFTP). These are examples of the core capabilities that allow applications to operate over a network. The other options relate to separate aspects: speed considerations concern bandwidth and performance; interference and attenuation deal with signal quality on the physical link; and ports are the access points used by services but don’t define the services themselves.