A company has developed a REST API using Amazon API Gateway's Regional endpoint to share data with six US-based partners. These partners access the API daily to submit sales figures. Post-deployment, the company notices a surge in traffic, with 1,000 requests per second from 500 distinct IP addresses globally, suspected to be from a botnet. The company aims to secure the API against this unauthorized access while minimizing costs. What strategy should the company adopt to enhance the API's security? | AWS Certified Solutions Architect - Professional Quiz