What happens to the sessions that are presently connected to the database Instance?

Your database is open and the LISTENER listener running. You stopped the wrong listener
LISTENER by issuing the following command:
1snrctl > STOP
What happens to the sessions that are presently connected to the database Instance?

A.
They are able to perform only queries.

B.
They are not affected and continue to function normally.

C.
They are terminated and the active transactions are rolled back.

D.
They are not allowed to perform any operations until the listener LISTENER is started.

Explanation:
The listener is used when the connection is established. The immediate impact of
stopping the listener will be that no new session can be established from a remote host. Existing
sessions are not compromised.