The Elastic Beanstalk option is incorrect because it requires a constantly-polling instance, which may
break and costs money.
The Lambda fleet option is incorrect because AWS Lambda does not support GPU usage.
The OpsWorks stack option both requires a constantly-polling instance, and also requires complex timing
and capacity planning logic.
The CloudFormation option requires no polling, has no always-on instances, and allows arbitrarily fast
processing by simply setting the instance count as high as needed.
Reference: http://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html

https://docs.aws.amazon.com/codepipeline/latest/userguide/integrations-action- type.html#integrations-invoke

The Query API for IAM and AWS STS lets you call service actions. Query API requests are HTTPS requests that must contain an Action parameter to indicate the action to be performed.
IAM and AWS STS support GET and POST requests for all actions, that is, the API does not require you to use GET for some actions and POST for others.
Reference: http://docs.aws.amazon.com/IAM/latest/UserGuide/programming.html

The scaling of CC2 Instances in the Autoscaling group is normally done with the metric of the CPU utilization of the current instances in the Autoscaling group For more information on scaling in your Autoscaling Group, please refer to the below link:
* http://docs.aws.a mazon.com/autoscaling/latest/userguide/as-scaling-si mple-step.html Amazon RDS Multi-AZ deployments provide enhanced availability and durability for Database (DB) Instances, making them a natural fit for production database workloads. When you provision a Multi-AZ DB Instance, Amazon RDS automatically creates a primary DB Instance and synchronously replicates the data to a standby instance in a different Availability Zone (AZ). Cach AZ runs on its own physically distinct, independent infrastructure, and is engineered to be highly reliable. In case of an infrastructure failure, Amazon RDS performs an automatic failover to the standby for to a read replica in the case of Amazon Aurora), so that you can resume database operations as soon as the failover is complete. For more information on RDS Multi-AZ please refer to the below link:
https://aws.amazon.com/rds/details/multi-az/
Option A is invalid because if you already have in-built metrics from Cloudwatch, why would you want to spend more in using a a third-party monitoring solution.
Option B is invalid because health checks are already a feature of AWS CLB Option C is invalid because the database CPU usage should not be used to scale the web tier.
Option C is invalid because increasing the instance size does not always guarantee that the solution will not become unhealthy.
Option F is invalid because increasing Read-Replica's will not suffice for write operations if the primary DB fails.

You are not guaranteed 10gigabit performance, except within a placement group. A placement group is a logical grouping of instances within a single Availability Zone. Using placement groups enables applications to participate in a low-latency, 10 Gbps network. Placement groups are recommended for applications that benefit from low network latency, high network throughput, or both.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html