You are designing a mobile timesheet application. Employees submit timesheets weekly, with most submissions on Fridays. Payroll administrators must run monthly reports from the stored data. The infrastructure must be highly available and scale with incoming submissions and reporting demand while minimizing operational overhead. Which combination of steps meets these requirements? (Choose two.)

The combination of S3, CloudFront, API Gateway, and Lambda provides a highly available, scalable, and serverless architecture for the application front end and backend, minimizing operational overhead. S3 hosts static assets, CloudFront caches content for low latency, API Gateway manages API requests, and Lambda executes backend logic, scaling automatically with demand. Storing timesheet data in S3 and using Athena with QuickSight for reporting offers a cost-effective, scalable, and serverless solution for analytics. S3 is ideal for large volumes of unstructured data, Athena allows direct querying of S3 data without provisioning servers, and QuickSight provides business intelligence capabilities. Incorrect options: EC2 On-Demand with scheduled Auto Scaling adds operational overhead and is less serverless than the chosen solution. ECS with scheduled Auto Scaling is better than EC2 but still involves managing containers and is not as fully serverless as Lambda. Redshift is a data warehouse optimized for complex analytical queries on structured data, but for raw timesheet submissions that are then queried with Athena, S3 is more flexible and cost-effective, especially for initial storage and ad-hoc queries.