Loose coupling between services can also be done through asynchronous integration.

It involves one component that generates events

and another that consumes them.

The two components do not integrate through direct point-to-point interaction,

but usually through an intermediate durable storage layer.

This approach decouples the two components

and introduces additional resiliency.

So, for example, if a process that is reading messages from the queue fails,

messages can still be added to the queue to be processed when the system recovers.

Reference:

https://www.botmetric.com/blog/aws-cloud-architecture-design-principles/

If you decided to create service accounts (that is, accounts used for programmatic access by applications running outside of the AWS environment)

and generate access keys for them,

you should create a dedicated service account for each use case.

This will allow you to restrict the associated policy to only the permissions needed for the particular use case,

limiting the blast radius if the credentials are compromised.

For example, if a monitoring tool and a release management tool both require access to your AWS environment,

create two separate service accounts with two separate policies

that define the minimum set of permissions for each tool.

Reference:

https://aws.amazon.com/blogs/security/guidelines-for-protecting-your-aws-account-while-using-programmatic-access/

EBS is like a hard drive for EC2 on AWS not on-premises, C is correct.

The customer is responsible for managing, support, patching

and control of the guest operating system

and AWS services

provided like EC2.

Reference:

https://www.whizlabs.com/blog/aws-security-shared-responsibility/

Data Center resilience is practiced through Availability Zones

across data centers

that reduce the impact of failures.

Fault isolation improvement can be made to traditional horizontal scaling

by sharding (a method of grouping instances into groups called shards,

instead of sending the traffic from all users to every node like in the traditional IT structure.)

Reference:

https://www.botmetric.com/blog/aws-cloud-architecture-design-principles/

The enterprise support plans supports technical account manager. Developer and business support plans are devoid of this facility.

Reference:

https://aws.amazon.com/premiumsupport/plans/

In short, B is the correct answer.

A lot of people will be to be confused with RDS autoscaling.

While RDS autoscale its storage as needed, it doesn't autoscale its instance type on demand.

Amazon ElastiCache for Redis is a great choice for implementing a highly available, distributed, and secure in-memory cache

to decrease access latency, increase throughput,

and ease the load off your relational

or NoSQL databases and applications.

ElastiCache can serve frequently requested items at sub- millisecond response times,

and enables you to easily scale for higher loads

without growing the costlier backend databases.

Database query results caching, persistent session caching, and full-page caching are all popular examples of caching with ElastiCache for Redis.

Reference:

https://aws.amazon.com/products/databases/real-time-apps-elasticache-for-redis/

D is correct, all other services are shared.

Answer is D as the maintenance of Data center is whole AWS responsibility.