The best answer is D. Confidentiality.
In the CIA triad, confidentiality means protecting information from unauthorized disclosure. It ensures that only authorized users, systems, or processes can view sensitive data.
The other choices are different security concepts:
A). Integrity means protecting data from unauthorized modification or destruction.
B). Availability means ensuring systems and data are accessible when needed.
C). Authentication means verifying the identity of a user, device, or process.
Since the question specifically asks about protecting sensitive information from unauthorized disclosure, confidentiality is the correct answer.