A car sales company maintains data about cars that are listed for sale in an are a. The company receives data about new car listings from vendors who…

This solution is the most cost-effective because it leverages a fully serverless architecture. For processing small files (5 KB), AWS Glue is more cost-efficient than a provisioned Amazon EMR cluster as you only pay for the resources used during the ETL job's execution. Orchestrating the workflow with S3 Event Notifications and AWS Lambda is a direct, low-cost, and event-driven approach, perfectly suited for triggering a process upon file upload. Amazon Athena is a serverless query service ideal for one-time queries on data in S3, charging only for the queries run. Finally, Amazon QuickSight provides a serverless, pay-per-session business intelligence service for dashboarding, completing the cost-optimized, scalable solution.

1. AWS Glue vs. Amazon EMR: The AWS documentation states

"AWS Glue is a serverless data integration service... you don’t need to create and manage the infrastructure." This contrasts with EMR

making Glue more cost-effective for event-driven

small-scale jobs.

Source: AWS Glue Developer Guide

"What is AWS Glue?"

Section: "When to use AWS Glue?".

2. Orchestration with Lambda and S3 Events: This is a standard serverless pattern. "You can use Amazon S3 event notifications to invoke a Lambda function to process data as it arrives in your S3 bucket." This is more direct and cost-effective for simple triggers than a full Step Functions workflow.

Source: AWS Lambda Developer Guide

"Using AWS Lambda with Amazon S3".

3. Amazon Athena for Ad-hoc Queries: "Athena is serverless

so there is no infrastructure to manage

and you pay only for the queries that you run." This makes it ideal for one-time

analytical queries on S3 data.

Source: Amazon Athena User Guide

"What is Amazon Athena?".

4. Amazon QuickSight for Dashboards: QuickSight offers serverless

pay-per-session pricing

which is highly cost-effective for dashboarding needs that may have variable usage. It integrates natively with Athena.

Source: Amazon QuickSight User Guide

"What Is Amazon QuickSight?".

5. Serverless Analytics Architecture: The combination of S3

Lambda

Glue

Athena

and QuickSight forms a common

cost-effective

serverless analytics pipeline on AWS

avoiding the fixed costs and management of provisioned clusters.

Source: AWS Whitepaper

"Serverless Data Analytics on AWS" (aws-serverless-data-analytics.pdf). This paper outlines the exact pattern described in option D as a best practice.