John Sgromolo works for the 20th-largest accounting firm in the United States, but he's not an accountant. He works with hard drives and various other types of computer equipment strewn across several desks. Sgromolo, spends his days culling together bits and pieces of data people think they have erased from existence months, even years, before. His findings have been used in cyber-crime cases and murder investigations. Sgromolo engages in: a. data mirroring b. data mining c. digital forensics d. data combing e. data sleuthing