Investigators responding to a breach begin working directly at the scene.

The correct answer is A because the scenario describes active control of evidence items at the scene and immediate collection of volatile or time-sensitive artifacts before laboratory processing begins. That is the stage where responders take custody of exhibits and collect time-bound data. CHFI v11 includes first response, documenting the electronic crime scene, evidence preservation, and collecting volatile information before it is lost. Option B refers to an earlier identification step, which happens before investigators begin assuming control and gathering transient evidence. Option C is not the core activity described, and option D belongs to a later phase once evidence has already been seized and moved for laboratory examination. In forensic practice, the moment investigators secure relevant systems and start preserving live, rapidly changing information is a critical scene assessment and evidence-preservation phase. This may include capturing active sessions, running processes, open network connections, or displayed information. Since the question highlights both custody and the urgency of collecting time-sensitive artifacts at the scene, the best answer is taking custody of exhibits and collecting time-bound data.