Amazon Web Services Updated SAA-C03 Exam Questions and Answers by alvey

AWS Global Accelerator is the best answer because it providesstatic anycast IP addressesand routes users to the optimal healthy endpoint over the AWS global network. AWS documentation explains that Global Accelerator continuously monitors endpoint health and redirects traffic to the next best healthy endpoint almost immediately, which avoids dependence on DNS resolver caching or client-side IP caching. That is especially important for low-latency global applications such as Voice over IP. Route 53 geolocation routing does not provide the same fast failover characteristics, and CloudFront is not the service for generic bidirectional VoIP application traffic. (docs.aws.amazon.com)

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For secure communication between Lambda and an RDS DB instance, AWS documentation recommends placing the Lambda functions inside the same VPC and controlling traffic using security groups.

Lambda should have a dedicated security group with outbound access to the VPC CIDR range, and the DB instance’s security group should explicitly allow inbound connections from the Lambda security group. This follows the " least privilege " principle while avoiding public exposure.

Options A and B expose the DB to unnecessary risk. Option D is insecure because it bypasses security groups.

The correct and secure approach is to use Amazon CloudFront with Origin Access Control (OAC) to protect the S3 origin and attach AWS WAF to the CloudFront distribution to inspect and filter traffic at the edge before reaching the origin.

From AWS Documentation:

“AWS WAF is integrated with Amazon CloudFront, allowing inspection of HTTP(S) requests at the edge location before forwarding to your origin. To restrict direct access to the S3 bucket, use Origin Access Control (OAC).”

(Source: Amazon CloudFront Developer Guide – Serving private content)

Why Option D is correct:

CloudFront is the only service that integrates with AWS WAF for full HTTP layer inspection.

Origin Access Control (OAC) ensures that only CloudFront can access the S3 origin—replacing older Origin Access Identity (OAI) features.

The S3 bucket policy is configured to trust requests only from CloudFront using OAC signed requests.

Why the other options are incorrect:

Option A: WAF ARN is not a principal in S3 bucket policy. IAM does not support bucket policies based on WAF ARNs.

Option B: Incorrect – CloudFront doesn ' t " forward requests to WAF " ; rather, WAF is associated with CloudFront and inspects requests at the edge.

Option C: S3 does not use security groups; they are for EC2/network interfaces. This shows a misunderstanding of how S3 works.

Amazon CloudFront can usemultiple originsin one distribution, including anAmazon S3 bucketfor static content and anApplication Load Balancerfor dynamic content. That lets the company reduce latency globally for both content types while keeping a single front door for users. AWS documentation specifically notes that CloudFront supports both S3 origins and load balancer origins, and a single distribution can include multiple origins. Route 53 can then alias the company’s domain to the CloudFront distribution. The Global Accelerator options are unnecessary here because CloudFront already addresses the performance need for both static and dynamic web delivery in this architecture.

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