Answer: Amazon Route 53

The correct answer is C, Amazon Route 53. Amazon Route 53 is a highly available and scalable Domain Name System (DNS) web service provided by AWS. It includes a feature called 'DNS Failover' that can detect an outage of your website servers and automatically redirect users to alternate servers or locations where your application is operating properly. This ensures high availability and resiliency for web applications and websites. The other options are incorrect because Amazon CloudFront is a content delivery network service, Amazon GuardDuty is a threat detection service, and AWS Trusted Advisor provides guidance on AWS best practices.

Author: LeetQuiz Editorial Team