Comprehensive Detailed Explanation:
A cost-effective system integration design must balance the level of risk with the controls implemented to mitigate that risk. This balance ensures that resources are used efficiently while maintaining acceptable protection levels.
A, B, and C are relevant considerations, but only D represents the fundamental balance in security system design.
References:
PSP Study Guide - Security System Design and Risk-Based Planning
POA Manual - Cost-Effective Security Integration Principles