An AWS application reads messages from an SQS queue and processes them in batches, then sends results to another SQS queue consumed by a legacy system. The legacy system can take up to 5 minutes to process some messages and cannot be changed. The developer must prevent out-of-order updates in the legacy system. Which solution meets this requirement?

The correct solution is to use an SQS FIFO queue and configure the visibility timeout appropriately. An SQS FIFO (First-In, First-Out) queue guarantees message ordering, which is crucial for preventing out-of-order updates in the legacy system. The visibility timeout prevents other consumers from processing a message until the current consumer has successfully processed and deleted it, ensuring that the legacy system has enough time (up to 5 minutes) to complete its processing without duplicates or reordering. Using a standard SQS queue does not guarantee message ordering, making it unsuitable for this requirement. SendMessageBatchRequestEntry is for sending multiple messages in a single request, not for ensuring order or preventing out-of-order updates. DelaySeconds delays the delivery of a message to the queue, which is not relevant to maintaining processing order once a message is consumed.