What action would you take to overcome this error without disrupting any existing database communications?

You manually create an additional listener process, L1, for databases PROD, PAYDB and
FINDB. While starting up the listener process, you get the following error message:
LSNRCTL> start l1 Starting /u01/app/oracle/product/10.1.0/db_1/bin/tnslsnr: please wait…
TNSLSNR for Linux: Version 10.1.0.2.0 – Production System parameter file is
/u01/app/oracle/product/10.1.0/db_1/network/admin/listener.ora Log messages written to
/u01/app/oracle/product/10.1.0/db_1/network/log/l1.log Error listening on:
(ADDRESS=(PROTOCOL=TCP)(HOST=144.23.230.185)(port=8899)) TNS-12542:
TNS:address already in use TNS-12560: TNS:protocol adapter error TNS-00512: Address
already in use Linux Error: 98: Address already in use Listener failed to start. See the error
message(s) above… What action would you take to overcome this error without disrupting
any existing database communications?

A.
stop and restart the listener process

B.
change the IP address to host machine name in the LISTENER.ORA file and restart the
listener process

C.
change the port number to an unused port number and restart the listener process

D.
set the TNS_ADMIN environmental variable

E.
stop all running listener processes and restart the listener process