Explanation

Reserved Instances (C) and Savings Plans (D) are the correct answers because:

Reserved Instances (RIs)

• Allow you to make an upfront commitment (1-year or 3-year term) for EC2 instance usage
• Provide significant discounts (up to 72% compared to On-Demand pricing)
• Are specifically designed for production workloads with predictable usage patterns

Savings Plans

• Offer flexible pricing model with upfront commitment
• Provide similar discounts to Reserved Instances (up to 72% savings)
• Cover broader range of services beyond just EC2 instances
• Offer more flexibility in instance family, size, and region changes

Why other options are incorrect:

• Spot Instances (A): Offer the lowest cost but don't require upfront commitment and can be interrupted
• On-Demand Instances (B): No upfront commitment required, highest cost option
• Dedicated Hosts (E): Physical servers dedicated to your use, but typically more expensive and don't specifically offer the lowest cost for production workloads

Both Reserved Instances and Savings Plans provide the lowest cost for production workloads when you can make an upfront commitment for continued usage.