All of the following methods ensure the stored data are unreadable except…?
a. writing random data over the old file.
b. physical alteration of media.
c. degaussing the disk or tape.
d. removing the volume header information.

Option D i.e., Removing the volume header information is the correct option.

Explanation:

In the above statement, the volume header includes the data related to the volume of the hard drive and each of them includes an isolated header of the volume or its group.  

The size of the volume header is not greater than 1000-KB. It build at the time of the installation of an Operating System in the computer system.

do not use any of these common illegal characters/symbols:

# pound

% percent

& ampersand

{ left curly bracket

} right curly bracket

\ back slash

< left angle bracket

> right angle bracket

* asterisk

? question mark

/ forward slash

  blank spaces

$ dollar sign

! exclamation point

' single quotes

" double quotes

: colon

@ at sign