Answer: Purchase a No Upfront Compute Savings Plan for a 1-year term.

## Explanation The correct answer is **B. Purchase a No Upfront Compute Savings Plan for a 1-year term.** Here's why: ### Key Requirements: 1. **Optimize cost of Amazon EC2 instances** - Need cost savings 2. **Change instance type and family every 2-3 months** - Need flexibility ### Analysis of Options: **A. Purchase Partial Upfront Reserved Instances for a 3-year term.** - ❌ **Problem**: Reserved Instances are tied to specific instance types, families, and Availability Zones. They don't provide the flexibility to change instance types every 2-3 months. - ❌ **Problem**: 3-year term is too long for a company that needs to change configurations frequently. **B. Purchase a No Upfront Compute Savings Plan for a 1-year term.** - ✅ **Advantage**: Compute Savings Plans provide the **highest flexibility** - they apply to any instance family, size, region, OS, or tenancy within the same AWS account. - ✅ **Advantage**: No upfront payment means lower initial commitment. - ✅ **Advantage**: 1-year term aligns better with the requirement to change configurations every 2-3 months. - ✅ **Advantage**: Provides significant cost savings (up to 66%) while maintaining flexibility. **C. Purchase All Upfront Reserved Instances for a 1-year term.** - ❌ **Problem**: Same limitation as option A - Reserved Instances are locked to specific instance types and families. - ❌ **Problem**: All upfront payment with no flexibility to change instance types. **D. Purchase an All Upfront EC2 Instance Savings Plan for a 1-year term.** - ❌ **Problem**: EC2 Instance Savings Plans are more flexible than Reserved Instances but still have limitations: - They apply to a specific instance family (e.g., m5) and region - Cannot change to a different instance family (e.g., from m5 to c5) - ❌ **Problem**: All upfront payment reduces flexibility. ### Why Compute Savings Plan is Best: 1. **Maximum Flexibility**: Can switch between EC2 instance types, families, sizes, regions, OS, and tenancy 2. **Cost Savings**: Provides significant discounts (up to 66%) similar to Reserved Instances 3. **No Instance Lock-in**: Unlike Reserved Instances or EC2 Instance Savings Plans, Compute Savings Plans don't lock you into specific instance types 4. **1-year Term**: Shorter commitment aligns with the frequent change requirement 5. **No Upfront**: Lower financial commitment and better cash flow management ### Additional Considerations: - The company's requirement to change instance types every 2-3 months suggests they might be: - Testing different instance types for performance optimization - Responding to changing workload patterns - Migrating applications between instance families - Compute Savings Plans automatically apply to any eligible usage, making them ideal for dynamic environments where instance types change frequently. **Conclusion**: The Compute Savings Plan with no upfront payment and 1-year term provides the optimal balance of cost savings and flexibility for a company that needs to change EC2 instance types and families every 2-3 months.