A company needs a solution to process customer orders from a global ecommerce platform.

The correct answer isBbecause the company needs order processing to beginimmediatelywhen new orders arrive and also needs ahistory of all order processing attemptsin themost cost-effectiveway. Amazon EventBridge is a serverless event bus that can respond to events as they occur, which makes it a strong fit for near real-time order processing. By using anEventBridge event patternand a rule that invokesAWS Lambdawhen a new order event is received, the solution avoids polling and processes orders only when there is actual work to perform.

This event-driven design is more cost-effective than running scheduled checks or maintaining EC2 instances.AWS Lambdaprovides fully managed compute with automatic scaling and charges based on actual execution time.Amazon DynamoDBis a highly scalable and fully managed NoSQL database that is well suited for storing order-processing results and maintaining a durable history of processing attempts with low operational overhead.

Option A is incorrect because invoking Lambda every minute to check for new orders is a polling model, which introduces delay and unnecessary invocations. Option C is incorrect because using an EC2 instance to poll for events creates higher operational cost and overhead. Option D is less appropriate becauseAmazon EFSis not the best storage choice for durable event history or structured tracking of order-processing attempts.

AWS architectural guidance favorsevent-driven, serverless patternsfor asynchronous order processing when immediate response, scalability, and low cost are required. Therefore,EventBridge + Lambda + DynamoDBis the best solution.