The correct answer is A. Helping users understand the decisions made by an AI system.

According to the Microsoft Responsible AI principles described in the AI-900 study guide and Microsoft Learn Responsible AI documentation, transparency focuses on ensuring that users and stakeholders clearly understand how an AI system functions, makes decisions, and what data it relies on. This includes communicating limitations, assumptions, and levels of confidence in AI-driven outcomes.

For instance, if an AI model recommends loan approvals, transparency means explaining which factors influenced the decision and how much weight each factor carried. This helps build trust and accountability while allowing users to make informed judgments about the AI’s reliability.

Option review:

A. Helping users understand decisions made by an AI system — ✅ Correct.

B. Accountability: Refers to ensuring developers or organizations are responsible for AI outcomes.

C. Fairness: Ensures equal opportunities and mitigates bias.

D. Privacy and security: Focuses on protecting user data.

Hence, Transparency = clarity and explainability about AI processes.