Reference:

https://aws.amazon.com/blogs/aws/the-new-aws-tco-calculator/

The hardware related jobs is the prime responsibility of AWS.

VPC network access control lists is something a customer has to do himself to secure the applications.

Encrypting data in transit and at rest is a shared responsibility in which AWS plays a part.

All hardware related jobs have nothing to do with the customer.

Reference:

https://dzone.com/articles/aws-shared-responsibility-model-cloud-security

It's A & B. Elasticity is about scaling in and out.

C is about load balancing and therefore incorrect.

Spot Instances: short workloads, cheap, can lose instances (less reliable)

So A is the right answer!

The idea behind this question is what costs to consider if leaving the estate on prem.

B & C are on-prem expenses.

Answer is D: Pay per request and compute time!

A - Security Groups act as virtual firewall

- Backup and Restore: a simple, straightforward, cost-effective method that backs up and restores data as needed. Keep in mind that because none of your data is on standby, this method, while cheap, can be quite time-consuming.

- Pilot Light: This method keeps critical applications and data at the ready so that it can be quickly retrieved if needed.

- Warm Standby: This method keeps a duplicate version of your business' core elements running on standby at all times, which makes for a little downtime and an almost seamless transition.

- Multi-Site Solution:

Also known as a Hot Standby, this method fully replicates your company's data/applications between two or more active locations

and splits your traffic/usage between them.

If a disaster strikes, everything is simply rerouted to the unaffected area, which means you'll suffer almost zero downtime.

However, by running two separate environments simultaneously, you will obviously incur much higher costs.

Reference:

https://cloudranger.com/best-practices-aws-disaster-recovery-planning/

AWS TCO calculators allow you to estimate the cost savings when using AWS and provide a detailed set of reports that can be used in executive presentations.

The calculators also give you the option to modify assumptions that best meet your business needs.

Reference:

https://aws.amazon.com/tco-calculator/

The way that Reserved Instance discounts apply to accounts in an organization's consolidated billing family depends on whether Reserved Instance sharing is turned on or off for the account.

By default, Reserved Instance sharing for all accounts in an organization is turned on.

You can change this setting by Turning Off Reserved Instance Sharing for an account.

The capacity reservation for a Reserved Instance applies only to the account the Reserved Instance was purchased on, regardless of whether Reserved Instance sharing is turned on or off.

Reference:

https://aws.amazon.com/premiumsupport/knowledge-center/ec2-ri-consolidated-billing/