Comprehensive and Detailed Explanation From Exact Extract of AWS CloudOps Documents:

To secure inbound web traffic over HTTPS when using an Application Load Balancer, AWS CloudOps best practices recommend terminating TLS at the load balancer. This is achieved by attaching an SSL/TLS certificate directly to the ALB listener. Therefore, option B is required. By terminating HTTPS at the ALB, traffic between clients and the load balancer is encrypted, and the ALB can then forward traffic to backend EC2 instances using HTTP or HTTPS based on design requirements.

The certificate used for a public-facing retail website must be trusted by internet browsers. AWS Certificate Manager (ACM) public certificates are specifically designed for this purpose and are trusted by common browsers and operating systems. Therefore, option D is required. ACM manages certificate provisioning, renewal, and deployment automatically, which significantly reduces operational overhead.

Option A is incorrect because attaching certificates to each EC2 instance is unnecessary and does not scale well. Option C is incorrect because private certificates are intended for internal use cases and are not trusted by public browsers. Option E is incorrect because ACM-managed public certificates cannot be exported; they must be attached directly to supported AWS services such as ALBs.

This approach aligns with AWS CloudOps guidance for secure, scalable, and highly available HTTPS architectures.