Should be AC.

There are no upfront commitments (AWS is on-demand).

AWS does not manage all security in the cloud, it is a shared responsibility model.

Users do not get free unlimited storage, there are free tiers however they are capped at 12 months of usage.

Users have NO control over the physical infrastructure.

The answer is B.

Access keys are long-term credentials for an IAM user or the AWS account root user.

You can use access keys to sign programmatic requests to the AWS CLI or AWS API (directly or using the AWS SDK).

C.

AWS Trusted Advisor is an online tool that provides you real time guidance to help you provision your resources following AWS best practices.

Whether establishing new workflows, developing applications, or as part of ongoing improvement, take advantage of the recommendations provided by Trusted Advisor

on a regular basis to help keep your solutions provisioned optimally.

Reference:

https://aws.amazon.com/premiumsupport/technology/trusted-advisor/

Answer is B -> AWS Cost Explorer.

AWS Cost Explorer has an easy-to-use interface that lets you visualize, understand, and manage your AWS costs and usage over time.

Get started quickly by creating custom reports that analyze cost and usage data.

Analyze your data at a high level (for example, total costs and usage across all accounts) or dive deeper into your cost and usage data to identify trends, pinpoint cost drivers, and detect anomalies.

B. Elastic Load Balancing automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, Lambda functions, and virtual appliances.

It can handle the varying load of your application traffic in a single Availability Zone or across multiple Availability Zones.

Elastic Load Balancing offers four types of load balancers that all feature the high availability, automatic scaling, and robust security necessary to make your applications fault tolerant.

Answer is C.

AWS Artifact is your go-to, central resource for compliance-related information that matters to you.

References:

https://aws.amazon.com/artifact/

Reference:

https://aws.amazon.com/compliance/shared-responsibility-model/

HA is synonymous to failure and recovery. This is the keyword in the question which is only complemented by applications can absorb failures in one instance by handing over to another instance or more.

=> C is correct.

B is correct:

As application complexity increases, a desirable attribute of an IT system is that it can be broken into smaller, loosely coupled components.

This means that IT systems should be designed in a way that reduces interdependencies—a change or a failure in one component should NOT cascade to other components.

CloudWatch Logs reports on application logs, while CloudTrail Logs provide you specific information on what occurred in your AWS account.

CloudWatch Events is a near real time stream of system events describing changes to your AWS resources.

CloudTrail focuses more on AWS API calls made in your AWS account.