What is the effect of using CLI “config system session-ttl” to set session_ttl to 1800
seconds?

A.
After 1800 seconds, the end user must reauthenticate.

B.
After a session has been open for 1800 seconds, the FortiGate unit will send a keepalive
packet to both client and server.

C.
Sessions can be idle for no more than 1800 seconds.

D.
The maximum length of time a session can be open is 1800 seconds.