With step scaling, you choose scaling metrics and threshold values for the CloudWatch alarms that trigger the scaling process as well as define how your scalable target should be scaled when a threshold is in breach for a specified number of evaluation periods. Step scaling policies increase or decrease the current capacity of a scalable target based on a set of scaling adjustments, known as step adjustments.
The adjustments vary based on the size of the alarm breach. After a scaling activity is started, the policy continues to respond to additional alarms, even while a scaling activity is in progress. Therefore, all alarms that are breached are evaluated by Application Auto Scaling as it receives the alarm messages.
When you configure dynamic scaling, you must define how to scale in response to changing demand.
For example, you have a web application that currently runs on two instances and you want the CPU utilization of the Auto Scaling group to stay at around 50 percent when the load on the application changes. This gives you extra capacity to handle traffic spikes without maintaining an excessive amount of idle resources. You can configure your Auto Scaling group to scale automatically to meet this need.
The policy type determines how the scaling action is performed.

Amazon EC2 Auto Scaling supports the following types of scaling policies:
Target tracking scaling - Increase or decrease the current capacity of the group based on a target value for a specific metric. This is similar to the way that your thermostat maintains the temperature of your home - you select a temperature and the thermostat does the rest.
Step scaling - Increase or decrease the current capacity of the group based on a set of scaling adjustments, known as step adjustments, that vary based on the size of the alarm breach. Simple scaling - Increase or decrease the current capacity of the group based on a single scaling adjustment.
If you are scaling based on a utilization metric that increases or decreases proportionally to the number of instances in an Auto Scaling group, then it is recommended that you use target tracking scaling policies. Otherwise, it is better to use step scaling policies instead. Hence, the correct answer in this scenario is Step Scaling.
Target tracking scaling is incorrect because the target tracking scaling policy increases or decreases the current capacity of the group based on a target value for a specific metric, instead of a set of scaling adjustments.
Simple scaling is incorrect because the simple scaling policy increases or decreases the current capacity of the group based on a single scaling adjustment, instead of a set of scaling adjustments.
Scheduled Scaling is incorrect because the scheduled scaling policy is based on a schedule that allows you to set your own scaling schedule for predictable load changes. This is not considered as one of the types of dynamic scaling.
References:
https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-scale-based-on-demand.html
https://docs.aws.amazon.com/autoscaling/application/userguide/application-auto-scaling-step-scaling-pol icies.html

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/vpc-endpoints-dynamodb.html
https://aws.amazon.com/about-aws/whats-new/2019/09/amazon-eks-adds-support-to-assign-iam-permissions-to-