Which of the following find commands will print out a list of suid root files in /usr?

The `find` command with `/usr` specifies the starting directory. `-uid 0` correctly identifies files owned by the root user (UID 0). The `-perm +4000` test correctly finds files where the SUID bit (octal 4000) is set, as `+` means 'at least one of the bits in the mode is set'.

`+mode +s` are not valid `find` primaries for permission checks; the correct syntax for SUID permissions involves `-perm`.

`-type suid` is not a valid argument for the `-type` primary, and `-username` is not a standard `find` primary.

The `*s*` is a pattern for file names, not a permission test, and `-u root` is not the correct syntax for specifying user ownership.

`-suid` is not a standard `find` primary for locating SUID files; the correct way is to use the `-perm` primary.