Question：
What is the adbantage of managed recovery mode?
A. Druing recovery, most common DBA errors can be avoid.
B. Prompts for applying the next available redo logs suppressed.
c. The primary database automatically ships archived redo log files to the standby server.
D. The standby database automatically applies the archived redo log when the files become available;
(选什么，为什么？）
