Correct answer - "CodeBuild scales automatically" : CodeBuild runs build in parallel
automatically and has a 20 concurrent build limit that you can increase.
"Increase the instance types for your CodeBuild instances" - Changing the instance type has
nothing to do with parallel builds
"Run CodeBuild in an ASG" - CodeBuild is a managed service that scales on demand
"Enable CodeBuild Auto Scaling" - It scales automatically