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.annually

B.
/etc/cron.hourly

C.
/etc/cron.daily

D.
/etc/cron.minutely

E.
/etc/cron.monthly

F.
/etc/cron.yearly