what is the purpose of the Log Transport Services?

In the Oracle 10g Data Guard architecture, what is the purpose of the Log Transport Services?

A.
to control the automated transfer or redo data from the production database to one or more archival destinations

B.
to apply redo log records sent from the primary database to a stadby database at the receiving location

C.
to synchronize changes to the control files on all standby database with changes on the primary database when a log switch occurs

D.
to batch archived log files on the primary database until a defined number of checkpoints have been processed and then to distribute the arcives to each standby database

Explanation:
A – True. Redo Transport Services control the automated transfer of redo data from the production database to one or more archival destinations. Redo transport services also perform the following tasks:
* Transmit redo data from the primary system to the standby systems in the configuration
* Manage the process of resolving any gaps in the archived redo log files due to a network failure
* ENforce the database portecion modes;
* Automatically detect missing or corrupted archived redo log files on a standby system and automatically retrieve replacement archived redo log files from the primary database or another standby database
B – False . Apply redo service do this
C – False . Apply redo service do this
D – False

REF: Oracle(r) Data Guard Concepts and Administration 10g Release 2 (10.2), 1-3