You are a penetration tester, and you are discussing the CIA triad model with a colleague. You are discussing the meaning of the word confidentiality. In the context of the CIA triad model, which statement best describes what confidentiality means?

A. Preventing unauthorized access to information or systems

B. Preventing unauthorized modifications to information or systems

C. Ensuring that legitimate use of information and systems remains possible

D. Preventing legitimate access to information and systems