Which of the following is a standard Unix command that would most likely be used to copy raw file system data for later forensic analysis?

dd reads and writes raw data block-by-block from a source to a destination, preserving every bit including deleted files, slack space, and file system metadata. This makes it ideal for forensic acquisition because the resulting image is an exact duplicate of the original media. It is widely accepted in digital forensics for creating court-admissible disk images.

backup is not a standard Unix command; it is a non-standard or system-specific utility that does not produce raw forensic images.

cp copies files and directories at the file system level, skipping unallocated space and deleted data, making it unsuitable for forensic purposes.

gzip is a compression utility, not a data copying or imaging tool, and cannot be used alone to acquire raw disk images.