Which of the following is the BEST way to ensure accounts in a cloud environment are disabled as soon as they no longer need to be active?

Which of the following is the BEST way to ensure accounts in a cloud environment are disabled as soon as they no longer need to be active?
A. Have the user contact the cloud systems administrator to disable the account when it is no longer needed.
B. When users leave the company, ensure an account disablement request is initiated and will be fulfilled in less than four hours.
C. Have accounts checked by the cloud systems administrator once per day to ensure active accounts are still valid.
D. Reboot directory services servers once a day to ensure all account disablement requests are committed.