Which command can be used to change the file-system parameters to make all of the partition available to users, WITHOUT losing data?

The administrator notices that a 10GB ext2 file-system used only for data storage has
approximately 540MB reserved for root. Which command can be used to change the
file-system parameters to make all of the partition available to users, WITHOUT losing
data? Please enter only the command without path, options or parameters.

A.
tune2fs