Which log type will confirm whether users are trying to connect to the correct port?

Users are struggling to connect to a single public-facing development web server using its public IP address on a unique port number ot 8181. The security group is correctly configured to allow access on that port and the network ACLs are using the default configuration

Which log type will confirm whether users are trying to connect to the correct port?
A . AWS CloudTrail logs
B . Elastic Load Balancer access logs
C . Amazon S3 access logs
D . VPC Flow Logs

Answer: D