ECIH forensic readiness guidance identifies the Windows Registry as a primary source for USB device artifacts. The EnumUSB registry key stores vendor IDs, product IDs, serial numbers, and connection history.

Option A is correct because it provides direct evidence of which USB devices were connected, when they were installed, and on which system---critical for insider investigations.

Option B cannot reliably identify physical USB usage. Option C contains driver installation data but is less comprehensive. Option D is irrelevant.

Registry analysis is a foundational forensic technique in ECIH, making Option A correct.