Which statement is true about Oracle Net Listener?（）

• A、It acts as the listening endpoint for the Oracle database instance for all local and non-local user connections.
• B、A single listener can service only one database instance and multiple remote client connections.
• C、Service registration with the listener is performed by the process monitor (PMON) process of each database instance.
• D、The listener.ora configuration file must be configured with one or more listening protocol addresses to allow remote users to connect to a database instance.