Your team creates an Application Load Balancer for a new application and registers a Lambda function as its target. Three availability zones are enabled for the ALB. You want to take some actions to reduce the cost. Which of the below options is the most appropriate?

Answer options:

A.Replace the Lambda function with an EC2 Auto Scaling Group as the ELB target.
B.Enable only one availability zone in the Application Load Balancer.
C.Modify the ELB listener to be TCP with a customized port.
D.Optimize the Lambda function so that the function executes the code faster.

Correct Answer – D
Option A is incorrect: Because the Lambda function is serverless and costs less than an Auto Scaling Group in most cases.
Option B is incorrect: Because ALB does not charge users based on the number of enabled availability zones. This method does not help.
Option C is incorrect: Because Application Load Balancer listeners can only be HTTP or HTTPS. TCP cannot be configured.
Option D is CORRECT: Because the Lambda function`s cost will be reduced if the execution duration decreases.
Reference:
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html.
https://aws.amazon.com/elasticloadbalancing/pricing/.
https://aws.amazon.com/lambda/pricing/