AWS Certified Cloud Practitioner (CLF-C02) — Question 417

A company needs to purchase Amazon EC2 instances to support an application that will run continuously for more than 1 year.

Which EC2 instance purchasing option meets these requirements MOST cost-effectively?

Answer options

• A. Dedicated Instances
• B. Spot Instances
• C. Reserved Instances
• D. On-Demand Instances

Correct answer: C

Explanation

Reserved Instances are the most cost-effective choice for continuous workloads running for a year or more because they offer a significant discount in exchange for a 1-year or 3-year commitment. Spot Instances are unsuitable because they can be interrupted and terminated by AWS at any time, which does not support continuous application availability. On-Demand and Dedicated Instances do not offer the long-term commitment discounts needed to minimize costs for this predictable, ongoing workload.