Which TWO statements about crontab are true?

Which TWO statements about crontab are true?

A.
A cron daemon must run for each existing crontab.

B.
Every user may have their own crontab.

C.
The cron daemon reloads crontab files automatically when necessarly.

D.
Changing a crontab requires a reload/restart of the cron deamon.

E.
hourly is the same as "0 * * * *".

Explanation:
man crontab