A Company Asked You Help Mitigate the Brute Force Attacks

Multiple Choice

A company asked you help mitigate the brute force attacks carried out against its users' Windows account passwords. You successfully removed the malware responsible for the attacks and need to better secure the passwords assigned to the user accounts without limiting the system's usability.  
Which of the following should be included in securing the user accounts? (Select THREE.)

A) Require user account passwords.
B) Require strong passwords.
C) Change each account type to Administrator.
D) Add each user to the Guests group.
E) Set failed logon restrictions.
F) Disable password complexity requirements.