Louis, a professional hacker, had used specialized tools or search engines to encrypt all his browsing activity and navigate anonymously to obtain sensitive/hidden information about official government or federal databases. After gathering the information, he successfully performed an attack on the target government organization without being traced.
Which of the following techniques is described in the above scenario?

A. Website footprinting
B. Dark web footprinting
C. VPN footprinting
D. VoIP footprinting