Where are user specific crontabs stored?
A. In the database file /etc/crontab.db which is shared by all users.
B. As individual per-user files within /var/spool/cron.
C. As individual per-user files in /etc/cron.user.d.
D. In the .crontab file in the user's home directory.
E. In the file /var/cron/user-crontab which is shared by all users.