An Application Runs on Amazon EC2 Instances Across Multiple Availability

An application runs on Amazon EC2 instances across multiple Availability Zones. The instances run in an Amazon EC2 Auto Scaling group behind an Application Load Balancer. The application performs best when the CPU utilization of the EC2 instances is at or near 40%. What should a solutions architect do to maintain the desired performance across all instances in the group?

A) Use a simple scaling policy to dynamically scale the Auto Scaling group.
B) Use a target tracking policy to dynamically scale the Auto Scaling group.
C) Use an AWS Lambda function to update the desired Auto Scaling group capacity.
D) Use scheduled scaling actions to scale up and scale down the Auto Scaling group.