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.