View the Exhibit and examine the output. 
A. The ORCL instance is registered dynamically with the listener.
B. The ORCL instance is registered statically in the listener.ora file.
C. The number of current client connections handled by the service handler is two.
D. The total number of client connections handled so far by the service handler is two.
状态为 UNKONW 表明为静态注册，established：2 代表到目前建立了两个连接
