Answer:c. digital forensics
Explanation:Digital forensic refers to the computer evidence that is identified and extracted in order to be used in court. Basically it is a science of finding digital evidence from a computer,mobile phone,server or netowrk.
According to John Sgromolo there are multiple layers of history that are found on every computer and disk.
The operating system may not indicate their presence but they are still there.
He said that a person can open a file, type on it and not save it , even if they typed only a single letter but there is a historic mark of that action already recorded on the hard drive.
It will only require an expert to get rid of such evidence however even when that is done it can still be retrieved.
he said all of this on the Business news written August 14 2004 by David Reich Hale