A company runs its application on Amazon EC2 instances and AWS Lambda functions. The EC2 instances experience a continuous and stable load. The Lambda functions experience a varied and unpredictable load. The application includes a caching layer that uses an Amazon MemoryDB for Redis cluster. A solutions architect must recommend a solution to minimize the company's overall monthly costs. Which solution will meet these requirements? A. Purchase an EC2 instance Savings Plan to cover the EC2 instances. Purchase a Compute Savings Plan for Lambda to cover the minimum expected consumption of the Lambda functions. Purchase reserved nodes to cover the MemoryDB cache nodes. B. Purchase a Compute Savings Plan to cover the EC2 instances. Purchase Lambda reserved concurrency to cover the expected Lambda usage. Purchase reserved nodes to cover the MemoryDB cache nodes. C. Purchase a Compute Savings Plan to cover the entire expected cost of the EC2 instances, Lambda functions, and MemoryDB cache nodes. D. Purchase a Compute Savings Plan to cover the EC2 instances and the MemoryDB cache nodes. Purchase Lambda reserved concurrency to cover the expected Lambda usage.