The tnsnames.ora file has an entry for the service alias ORCL as follows:The TNS ping command executes successfully when tested with ORCL; however, from the same OS usersession, you are not able to connect to the database instance with the following command:SQL > CONNECT scott/tiger@orcl What could be the reason for this?（）

A. The listener is not running on the database node.
B. The TNS_ADMIN environment variable is set to the wrong value.
C. The orcl.oracle.com database service is not registered with the listener.
D. The DEFAULT_DOMAIN parameter is set to the wrong value in the sqlnet.ora file.
E. The listener is running on a different port.