A. External testing is used to test attacks. It is also used to control circumvention attempts on the target's network perimeter that come from outside the target system, e.g., the Internet. B. Internal testing refers to attacks and control circumvention attempts on the target from within the perimeter. The main objective is to identify what would happen if the external network perimeter is successfully compromised or if an authorized user from within the network compromises the security of a specific resource on the network. For the given concern, the internal testing method is the most appropriate type of penetration testing. C. Blind testing is used by a penetration tester who has no knowledge of the target information system. D. Targeted testing is used when both the target's IT team and tester are provided with information related to the target and network design.