Which of the following is the conventional purpose of Linux UIDs that are lower than 100?

While UID 0 is reserved for the superuser (root), the entire range below 100 is not exclusively for superuser accounts; it encompasses many other non-root system accounts.

System administrator accounts typically have UIDs above the system reserved range, though `root` (UID 0) is the primary administrative account.

UIDs 0-99 (or sometimes up to 499 depending on the distribution and configuration) are typically designated for system accounts like `root`, `bin`, `daemon`, `sys`, `adm`, and `lp`. These accounts are essential for the operation of system services and processes and are not intended for regular interactive user logins.

UIDs below 100 are actively used by numerous critical system services and are essential for system operation, not unused targets of exploits.

UIDs are used to identify users, and GIDs (Group IDs) identify groups; while users often have a primary group with a matching GID, this statement doesn't explain the specific purpose of *low* UIDs.