Final answer:
The best technical control to reduce easily cracked passwords is implementing password complexity rules, which require users to create more secure passwords.
Step-by-step explanation:
The question is addressing the issue of how to reduce the number of easily cracked passwords among end-users following a password audit. Among the options provided, the BEST technical control to implement in order to reduce the incidence of easily cracked passwords would be C. Password complexity.
Password complexity rules require users to create passwords that incorporate a mix of uppercase letters, lowercase letters, numbers, and special characters, making them significantly more difficult to crack.
This is more effective than simply managing credentials, maintaining a password history, or providing security awareness training, although the latter can complement technical controls by educating users on the importance of using strong passwords.