A company has a highly dynamic batch processing job that uses many Amazon EC2 instances to complete it. The job is stateless in nature, can be started and stopped at any given time with no negative impact, and typically takes upwards of 60 minutes total to complete. The company has asked a solutions architect to design a scalable and cost-effective solution that meets the requirements of the job. What should the solutions architect recommend?

1. Implement EC2 Spot Instances.
2. Purchase EC2 Reserved Instances.
3. Implement EC2 On-Demand Instances.
4. Implement the processing on AWS Lambda.