Rebecca, a seasoned forensic investigator, has been called in to investigate a potential data leak...

Option A is the best answer. The wording appears to contain a typo, and in CHFI context this clearly points to the principle of data preservation . CHFI v11 emphasizes live acquisition , order of volatility , evidence preservation , and the need to collect volatile information before actions are taken that may destroy it. In an active breach on a running server, abruptly shutting the system down may destroy critical volatile evidence such as RAM contents, active network connections, running processes, logged-in sessions, encryption artifacts, and other transient indicators that may explain how the leak is occurring.

This is why CHFI distinguishes between live acquisition and dead acquisition and teaches investigators to determine the best acquisition method before taking action. Federal Rules of Evidence and the Best Evidence Rule are legal concepts, but they do not directly describe the operational mistake of powering off a live compromised server. Sanitizing target media applies to preparing destination media for acquisition, not preserving a live source system. Therefore, the key violated principle is the preservation of data, especially volatile evidence on a live system.