What is the purpose of Windows Defender?

Correct answer: Provide real-time antivirus and anti-malware protection

Option D is correct because Windows Defender (now branded as Microsoft Defender Antivirus) provides real-time scanning and protection against viruses, malware, spyware, and ransomware, and is the built-in security component of Windows for endpoint threat detection and remediation. Option A, scheduling system backups, is the function of Windows Backup or File History, not Defender. Option B, managing user passwords, is handled by Credential Manager and account policy settings, not by Defender. Option C, configuring network adapters, is performed through Device Manager or Network and Sharing Center, which are unrelated to antivirus functionality.