How do you resolve this problem without causing other security issues?

You receive a notification that long-lasting Telnet connections to a mainframe are dropped after an hour of inactivity. Reviewing SmartView Tracker shows the packet is dropped with the error:"Unknown established connection" How do you resolve this problem without causing other security issues? Choose the BEST answer.

A.
Increase the service-based session timeout of the default Telnet service to 24-hours.

B.
Create a new TCP service object on port 23 called Telnet-mainframe. Define a service-based 171
session Timeout of 24-hours. Use this new object only in the rule that allows the Telnet connections to the mainframe.

C.
Ask the mainframe users to reconnect every time this error occurs.

D.
Increase the TCP session timeout under Global Properties > Stateful Inspection.