A global software company is using Amazon EC2 Reserved and On-Demand Instance for all project-related work. They have different accounts created for each vertical like Finance, Project, HR, which are managed individually by account owners in each vertical. Management is looking for options to decrease these recurring charges. How could the management save monthly billing charges without impacting the performance?[Choose TWO]

Answer options:

A.Each account should launch a Spot Instance instead of using On-Demand Instance.
B.Each account should share Reserved Instance which they have purchased with other accounts.
C.create AWS organization and leverage consolidated billing feature to get the discounts on Amazon EC2.
D.Use Budgets to limit the charges incurred for using Amazon EC2.

Correct Answer – B and C
Consolidated Billing combines usage from all the accounts & billing is generated based on the total usage. Services like Amazon EC2, Amazon S3, etc. have volume pricing tiers where the overall charges decrease with more usage volume.
Option A is incorrect. However, this will save the cost but will impact the performance.
Spot Instance and On-demand Instance are very similar in nature. The main difference between these is commitment. In Spot Instance, there is no commitment. As soon as the Bid price exceeds the Spot price, a user gets the Instance. In an On-demand Instance, a user has to pay the On-demand rate specified by Amazon. Once they have bought the Instance, they have to use it by paying that rate.
In Spot Instance, once the Spot price exceeds the Bid price, Amazon will shut the instance. The benefit to users is that they will not be charged for the partial hour in which the Instance was taken back from them.
Spot instances are not always cheaper than on-demand. They can and do sometimes fluctuate wildly, even to very high per hour amounts, higher than the on-demand price at times
Option B is correct as Reserved Instance discounts can be applied to accounts in an organization, but Reserved Instance sharing has to be turned on or off for the account
For details, please refer to the below URL-
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-ri-consolidated-billing/
Option D is incorrect as the Budget will limit charges but will not provide discounts on services being used by various accounts.
For more information on using consolidated billing, refer to the following URLs-
https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/consolidated-billing.html
https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/useconsolidatedbilling-discounts.html