When defaults are too permissive across multiple Windows workstations, the most efficient and scalable fix is to enforce a standardized security baseline using Group Policy . The All-in-One guide explains that Windows provides extensive "security features" such as requiring complex passwords, limiting logon times, and controlling whether users can install applications-"and the list goes on to thousands of security features." It states that " To configure these features, you use group policies ," and that you configure them using the Group Policy Editor (gpedit.msc) .
This directly matches the scenario: repeated unauthorized attempts suggest the need to tighten multiple security settings consistently. While enabling account lockout policies (D) is one good control, the question is broader-"default security settings may be too permissive"-so the best action is to implement the overall appropriate group policy that can include lockout, password complexity, auditing, and other controls together.
Updates and password resets are useful, but they don't systematically correct permissive baseline settings across systems. Therefore, implementing an appropriate group policy is the best answer.