CloudFormation Resource Explanation

Answer - D.

The intrinsic function Fn::GetAtt returns the value of an attribute from a resource in the template.

This has nothing to do with adding parameters (Option A is wrong) or allowing endpoints (Option B is wrong) or invoking relevant calls (Option C is wrong).

For more information on Fn:: GetAtt function, please refer to the below link.

The resource being referred to in the question is an AWS CloudFormation resource that creates an Amazon SNS (Simple Notification Service) topic. SNS is a fully managed messaging service that enables the pub/sub (publish/subscribe) messaging pattern for exchanging messages between applications, microservices, and other distributed systems.

The question presents four possible answers, and the correct answer is D: "Creates an SNS topic and adds a subscription ARN endpoint for the SQS resource created under the logical name SQSQueue." This means that the CloudFormation template creates an SNS topic and subscribes an Amazon SQS (Simple Queue Service) queue to it.

When creating an SNS topic in CloudFormation, the topic can have zero or more subscribers, which are the endpoints that receive messages published to the topic. In this case, the subscriber is an SQS queue, which is a fully managed message queuing service that enables decoupling and scaling of distributed systems.

The logical name of the SQS queue is specified in the CloudFormation template as SQSQueue. The subscription ARN (Amazon Resource Name) endpoint for the SQS queue is added to the SNS topic so that the topic can push messages to the queue.

To summarize, the resource in the CloudFormation template creates an SNS topic and subscribes an SQS queue to it by adding the subscription ARN endpoint for the SQS queue to the topic. This enables decoupling and scaling of distributed systems by allowing multiple subscribers to receive messages published to the SNS topic.