问题：

[单选] Which statement is true regarding RMAN components？（）

A . Each target database requires its own recover catalog. 
B . RMAN scripts can be stored in the recovery catalog or the target control file. 
C . A channel is a stream of data to a device type and corresponds to one server session. 
D . The RMAN executable interprets sever session commands and establishes connections to the target database.