AWS Certified Solutions Architect – Associate (SAA-C02) — Question 258

A company is moving its on-premises applications to Amazon EC2 instances. However, as a result of fluctuating compute requirements, the EC2 instances must always be ready to use between 8 AM and 5 PM in specific Availability Zones.
Which EC2 instances should the company choose to run the applications?

Answer options

• A. Scheduled Reserved Instances
• B. On-Demand Instances
• C. Spot Instances as part of a Spot Fleet
• D. EC2 instances in an Auto Scaling group

Correct answer: A

Explanation

Scheduled Reserved Instances are the best choice because they allow the company to reserve capacity for specific time frames, ensuring availability during peak hours. On-Demand Instances would incur higher costs for consistent use, while Spot Instances may not be reliable due to potential interruptions. EC2 instances in an Auto Scaling group may not guarantee availability during the specified hours unless configured properly.