What is the enumeration technique used by Henry on the organization?

Henry is a penetration tester who works for XYZ organization. While performing enumeration on a client organization, he queries the DNS server for a specific cached DNS record. Further, by using this cached record, he determines the sites recently visited by the organization’s user .

What is the enumeration technique used by Henry on the organization?
A . DNS zone walking
B . DNS cache snooping
C . DNS SEC zone walking
D . DNS cache poisoning

Answer: D