Final answer:
TN3270 is a telnet standard for the 3270 data stream, allowing users to access mainframe applications remotely.
Step-by-step explanation:
TN3270 refers to a telnet standard for the 3270 data stream. It is used to establish a connection between a mainframe computer and a remote terminal. This protocol allows users to access mainframe applications and data from a computer located elsewhere on the network.
For example, if a company has a mainframe computer running legacy 3270 applications, TN3270 would enable employees to access these applications using a computer in a different location.
Therefore, option C is the correct description of TN3270.