Windows Vista and Windows 7 offer a security feature which limits privileges of software applications and access to administrative tasks. When a program makes a change that requires administrator-level permission or a user attempts to modify system settings that require administrative access, it triggers an on-screen prompt requiring an administrator password to proceed. This functionality is called:
A. User Account Control (UAC)
B. Trusted Platform Module (TPM)
C. Windows Firewall
D. Windows Defender real-time protection