Which three are valid directories for cron jobs to be run at known intervals?

Which three are valid directories for cron jobs to be run at known intervals?

A.
/etc/cron.hourly

B.
/etc/cron.daily

C.
/etc/cron.minutely

D.
/etc/cron.monthly

E.
/etc/cron.yearly

F.
/etc/cron.annually

Explanation:
An alternative to editing the crontab is to place executable scripts into one of the
following directories. The script will be run at the appropriate interval.
/etc/cron.hourly
/etc/cron.daily
/etc/cron.weekly
/etc/cron.monthly
This is actually using anacron, rather than cron, but it achieves a similar goal.
Reference: http://www.oracle-base.com/articles/linux/cron-on-linux.php