PAM, or Pluggable Authentication Modules, are used in Linux environments to integrate multiple low-level authentication schemes into a high-level API that allows for programs that rely on authentication to be written independently of the underlying authentication mechanism. By configuring the PAM module responsible for password quality control, typically pam_pwquality.so, the administrator can enforce password strength policies. The configurations can include requirements for different character classes, minimum length, and other password policies. The other options, such as chage, passwd, and faillock, do not directly allow an administrator to enforce password strength requirements, as they serve different purposes in user account and password management.