What is the purpose of banner grabbing?

The correct answer is C because banner grabbing is used for identification during reconnaissance, scanning, and enumeration. Banner grabbing collects information returned by a service when a connection is made to an open port. This banner may disclose the application name, service type, operating system, software version, web server details, mail server details, or firmware/vendor information. CEH scanning methodology associates banner grabbing and OS fingerprinting with identifying the operating system and services running on target machines. The material also defines banner grabbing as an enumeration technique used to provide information about a computer system, generally for operating system identification or fingerprinting. It is not sniffing, because sniffing captures network traffic. It is not cracking, because cracking attempts to break passwords or protections. It is also not exploitation, although the information discovered may later help select an exploit. Therefore, the main purpose of banner grabbing is identification.