AWS Certified Solutions Architect – Associate (SAA-C03) — Question 977

A company needs guaranteed Amazon EC2 capacity in three specific Availability Zones in a specific AWS Region for an upcoming event that will last 1 week.
What should the company do to guarantee the EC2 capacity?

Answer options

• A. Purchase Reserved Instances that specify the Region needed.
• B. Create an On-Demand Capacity Reservation that specifies the Region needed.
• C. Purchase Reserved Instances that specify the Region and three Availability Zones needed.
• D. Create an On-Demand Capacity Reservation that specifies the Region and three Availability Zones needed.

Correct answer: D

Explanation

On-Demand Capacity Reservations guarantee compute capacity in a specific Availability Zone and can be created or canceled at any time, making them perfect for short-term events like a one-week duration. Regional Reserved Instances provide billing discounts but do not offer capacity guarantees, while capacity reservations must specify both the Region and the target Availability Zones to guarantee the capacity exactly where it is needed.