5 basic pillars according to AWS are (see https://aws.amazon.com/architecture/well-architected/?wa-lens-whitepapers.sort-by=item.additionalFields.sortDate&wa-lens-whitepapers.sort-order=desc):

1- Operational excellence

2- Security

3- Reliability

4- Performance efficiency

5- Cost optimization

The host is DEDICATED to you. You don't pay per hour. All Upfront is the correct answer.

Answer B as Availability Zones are for higher availability.

Availability Zones are multiple, isolated locations within each Region. If a Natural disaster affects a Region then it may impact all Availability zones.. Hence A is not an option

B is correct - The AWS Simple Monthly Calculator is an easy-to-use online tool that enables you to estimate the monthly cost of AWS services for your use case based on your expected usage. The AWS Simple Monthly Calculator is continuously updated with the latest pricing for all AWS services in all Regions.

Reference:

https://aws.amazon.com/blogs/apn/amazon-vpc-for-on-premises-network-engineers-part-one/

Key to the question is "recurring set of IP addresses".

So answer is D.

From the link: https://aws.amazon.com/waf/

"For example, you can filter any part of the web request, such as IP addresses, HTTP headers, HTTP body, or URI strings. This allows you to block common attack patterns, such as SQL injection or cross-site scripting. "

Reference:

https://asperbrothers.com/blog/infrastructure-as-code-aws/

Key word is dedicated network.

You can use AWS Direct Connect to establish a private virtual interface from your on-premise network directly to your Amazon VPC, providing you with a private, high bandwidth network connection between your network and your VPC. With multiple virtual interfaces, you can even establish private connectivity to multiple VPCs while maintaining network isolation.

Reference:

https://aws.amazon.com/directconnect/

D is correct Answer - Athena is a query service that can access Amazon S3.

AWS CloudFormation provides a common language for you to model and provision AWS and third party application resources in your cloud environment. AWS CloudFormation allows you to use programming languages or a simple text file to model and provision, in an automated and secure manner, all the resources needed for your applications across all regions and accounts. This gives you a single source of truth for your AWS and third party resources.

Reference:

https://aws.amazon.com/cloudformation/