C & D is correct.

As elasticity makes feasible to add/remove required resources as needed.

Pay-as-you-go - makes to pay based on usage only.

Edge locations are NOT located in AZs.

AZs are DCs (made of 1 or more DC per AZ) within a region.

=> B is answer.

https://aws.amazon.com/es/rds/

The link says one of the RDS benefits as easy to administer.

=> Hence Answer is A

B - not as this is true about S3.

C - not as this is true about Amazon Aurora.

D - not as RDS is scalable but not automatic.

Notes:

-Agility is the practice of “building in” the ability to change quickly and inexpensively.

-Elasticity as "The ability to acquire resources as you need them and release resources when you no longer need them."

-Pay-as-you-go pricing allows you to: Adapt to changing business needs without overcommitting budgets

=> B is correct

Answer is C.

NOT B because this is not always the case for AWS-managed services.

In fact, it is possible that the customer-managed services can outperform the AWS-managed services based upon the class, type or size of EC2 instance being used.

NOT D because customers can still choose and optimize the underlying instance being used for their RDS, Elasticache, and CloudSearch service.

A. AWS Config : auditing of changes to configurations, correct.

B. AWS Trusted Advisor : best practice assessments, wrong.

C. Amazon CloudWatch : performance monitoring, wrong.

D. Amazon Inspector : automated security assessments, wrong.

Answer is A.

The keyword here is "detailed level".

That's done with allocation tags. Budget report aren't that detailed.

More Hints:

Option A can see costs and categorize them on detail levels.

Option C only to see the overall cost and set up the overall cost for the budget.

Load Balancing = Distributing load.

Auto scaling = Changing/Adjusting loads. Hence, answer is D.

Correct answer is C - Cloud (deployment model) because all physical IT infrastructure has now moved to the cloud which allows the customer to walk away from a lot of their past Capital expenses ( purchasing servers, network routers and other physical IT infrastructure.)

A is INCORRECT because On-Premises is at the physical customer site and involves High Capital expenses.

B is INCORRECT because the question is looking for something to FULLY trade their capital expense ( local site servers, network etc.) for operational expenses.

Hybrid model will only trade part of the capital expenses because there are still pieces of the IT infrastructure still at the customer site.

Answer D ( PaaS) is INCORRECT because it is a Cloud Computing model ( NOT a Cloud Deployment model ).

C.

Agility ----- keyword ---> "Quickly"