Which two statements are true regarding Health Monitor checks in Oracle Database 11g?(Choose two.)

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Which two statements are true regarding Health Monitor checks in Oracle Database 11g?(Choose two.)

A. Health Monitor checks are always initiated manually when there is some critical error.
B. Health Monitor checks can be used to scan the contents of the redo log and archive logs for accessibility and corruption
C. Health Monitor checks can be used to verify the contents of dictionary entries for each dictionary object and fix it automatically.
D. Health Monitor checks can be used to verify the integrity of database files and report failures if these files are inaccessible, corrupt or inconsistent.