AWS Certified SysOps Administrator – Associate (legacy) — Question 279

An organization has added 3 of his AWS accounts to consolidated billing. One of the AWS accounts has purchased a Reserved Instance (RI. of a small instance size in the US-East-1a zone. All other AWS accounts are running instances of a small size in the same zone. What will happen in this case for the RI pricing?

Answer options

• A. Only the account that has purchased the RI will get the advantage of RI pricing
• B. One instance of a small size and running in the US-East-1a zone of each AWS account will get the benefit of RI pricing
• C. Any single instance from all the three accounts can get the benefit of AWS RI pricing if they are running in the same zone and are of the same size
• D. If there are more than one instances of a small size running across multiple accounts in the same zone no one will get the benefit of RI

Correct answer: C

Explanation

AWS Consolidated Billing allows the financial benefits of Reserved Instances (RIs) to be shared among all linked accounts within the organization. Because only one RI was purchased, the discount will be applied to exactly one matching instance (same size and Availability Zone) running in any of the consolidated accounts. It is not restricted to the purchasing account, nor does it apply to multiple instances at the same time.