Correct answer - "us-east-1" : If you don't select a region, then us-east-1 (US Virginia) will be
used by default, which happens to be the first region AWS started in and where most of the AWS
services reside.
"us-east-2" - US East (Ohio) region is not the default region
"us-west-1" - US West (N. California) region is not the default region
"eu-west-1" - EU (Ireland) region is not the default region