In case neither cron.allow nor cron.deny exist in /etc/, which of the following is true?

A. Without additional configuration, no users may have user specific crontabs.
B. Without additional configuration, all users may have user specific crontabs.
C. The cron daemon will refuse to start and report missing files in the system's logfile.
D. When a user creates a user specific crontab the system administrator must approve it explicitly