The correct answer is A because live acquisition is the method used when a system is still running and investigators must capture volatile evidence before it disappears. CHFI v11 explicitly includes live acquisition, order of volatility, and collection of volatile information such as memory contents, active processes, cache data, and session information. Those are exactly the artifacts named in the question. Logical acquisition focuses on selected file-system level data and does not specifically address volatile runtime state. Sparse acquisition is a targeted collection method used to gather selected portions of data, not in-memory artifacts. Dead acquisition is performed after a system is powered down and is therefore unsuitable when the most important evidence would be lost at shutdown. In forensic practice, active servers may contain critical evidence in RAM, open network connections, injected code, encryption material, or running process details that cannot be reconstructed later from disk alone. Since the question centers on preserving volatile evidence from a still-powered system, the correct and most CHFI-aligned answer is live acquisition.