Which option is required to syslogd in order for it to accept remote log messages?

The `-s` option is not a standard `syslogd` option for enabling remote message reception; it is sometimes used for `secure` logging.

The `-r` option (or `--remote`) is typically used with `syslogd` to instruct the `syslog` daemon to listen for incoming log messages from remote machines. Without this option, the daemon usually only processes local log messages.

`remote` is a descriptor, not a standard command-line option for `syslogd`.

The `-l` option is not a standard `syslogd` option for enabling remote message reception; it might be used for `local` logging control in some implementations.