What is a key policy that should be part of the information security plan?

An Acceptable Use Policy (AUP) is a critical component of an information security plan, as it defines acceptable and unacceptable actions for system and resource usage. It ensures users understand their responsibilities, reducing risks from misuse or negligence. While account management (A), training (B), and remote access (D) policies are important, the AUP provides the broad foundational guidance for user behavior.