Cisco Umbrella provides cloud-delivered security that includes malware and content filtering through DNS. It is designed to block malicious domains, IP addresses, and URLs before they can reach your network or endpoints. * DNS-Layer Security: Cisco Umbrella uses DNS to prevent connections to known malicious sites by blocking the DNS request, thereby preventing the initiation of malicious connections. * Content Filtering: It also provides content filtering to block inappropriate or non-business-related websites based on customizable policies. Option D is the correct answer because Cisco Umbrella is specifically known for its DNS-layer security capabilities, including malware and content filtering. Reference: Cisco Umbrella Documentation: Cisco Umbrella Overview