A penetration tester has gained access to a network device that has a previously unknown IP range on an interface. Further research determines this is an always-on VPN tunnel to a third-party supplier.
Which of the following is the BEST action for the penetration tester to take?

A. Utilize the tunnel as a means of pivoting to other internal devices.
B. Disregard the IP range, as it is out of scope.
C. Stop the assessment and inform the emergency contact.
D. Scan the IP range for additional systems to exploit.