单选题What is the implication of this command?（）A The command produces an error because the retention time cannot be reduced. B All historical data is retained but the subsequent flashback data archives are maintained for only three years. C All historical d

The command produces an error because the retention time cannot be reduced. 

All historical data is retained but the subsequent flashback data archives are maintained for only three years. 

All historical data is purged and the new flashback data archives are maintained for three years. 

All historical data older than three years is purged from the flashback archive FLA1.