Choice "B" is correct. Microcomputer systems are sometimes characterized by weak file and data security, and are usually accessible by many office personnel. (Manual systems, in contrast, generally restrict one user from accessing other users' files.) Thus, it is usually easier (increased risk) for unauthorized persons to access and alter computer system files, especially microcomputer system files.
Choice "a" is incorrect. No difference exists between manual and computer-based systems for detecting transposition errors.
Choice "d" is incorrect. Transactions should always be authorized before they are executed and recorded, in both manual and computer-based systems.
Choice "c" is incorrect. Because computer-based processing imposes strict rules on input and processing, generally there are fewer random processing errors.