Which action takes place when a file checkpoint occurs?
A. The checkpoint position is advanced in the checkpoint queue.
B. All buffers for a checkpointed file that were modified before a specific SCN are written to disk by DBWn and the SCN is stored in the control file.
C. The Database Writer process (DBWn) writes all dirty buffers in the buffer cache to data files.
D. The Log Writer process (LGWR) writes all redo entries in the log buffer to online redo log files.