Consider the following scenario：  You have a directory， data， under the disk group tdgroup  A. You want to create an alias for one of the data files and you execute the following command： ALTER DISKGROUP tdgroupA  ADD ALIAS ’+tdgroupA/data/datafile.dbf’  FOR ’+tdgroupA. 231.45678’；  Which task would be accomplished by the command？（）

• A、A
• B、B
• C、C
• D、D
• E、E