Which of the following is a factor that affects the trustworthiness of an information system?

• A. Security Functionality
• B. Security Assurance
• C. Confidentiality
• D. Availability

Answer: (A)

Trustworthiness hinges on the security controls the system actually provides. Security functionality includes the built-in protections the system uses to enforce policy and protect data—things like authentication, authorization, encryption, auditing, and secure configuration. When these functions are robust and correctly implemented, the system can reliably prevent or mitigate threats, detect incidents, and respond appropriately, which directly boosts trust. While assurance (the confidence in those protections) and security properties like confidentiality and availability matter, they rely on the underlying functionality to be effective. So the presence and quality of security functionality is what most directly affects how trustworthy the information system is.