正解:A
"Technical controls enforce confidentiality, integrity, and availability in the digital space. Examples of technical security controls include firewall rules, access control lists, intrusion prevention systems, and encryption." A technical control is a type of control that uses technology or software to protect data and systems from unauthorized access or misuse3. A technical control can include encryption, authentication, firewalls, antivirus software, and other mechanisms that rely on hardware or software. Placing an ACL (access control list) on a file folder is an example of a technical control. An ACL is a list of permissions that specifies who can access or modify a file or folder4. An ACL can help to enforce confidentiality, integrity, and availability of data by restricting access to authorized users only.