Answer: Closed port
Explanation:
Port 23 basically refers to the telnet which provide very severe services and it is used to access the server remotely. We should always closed the port 23, when we are not using telnet services because to prevent it from being hacked due to the port scanning.
As, now a days it is rarely used by the hackers as it is difficult to access this services from the server.
Therefore, Closed port is the correct answer.
