How should a sysops administrator verify this?

A developer is deploying a web application on Amazon EC2 instances behind an Application Load Balancer (ALB) and notices that the application is not receiving all the expected elements from HTTP requests. The developer suspects users are not sending the correct query string

How should a sysops administrator verify this?
A . Monitor the ALB default Amazon CloudWatch metrics Verify that the requests contain the expected query string
B . Configure the ALB to store access logs within Amazon S3 Verify that log entries contain the expected query string
C . Open the ALB logs in Amazon CloudWatch Verify that requests contain the expected query string
D . Create a custom Amazon CloudWatch metric to store requests Verify that the metric contains the expected query string

Answer: A