Your system automatically provisions EIPs to EC2 instances in a VPC on boot. The system provisions the whole VPC
and stack at once. You have two of them per VPC. On your new AWS account, your attempt to create a Development
environment failed, after successfully creating Staging and Production environments in the same region. What happened?

A.
You didn’t choose the Development version of the AMI you are using.

B.
You didn’t set the Development flag to true when deploying EC2 instances.

C.
You hit the soft limit of 5 EIPs per region and requested a 6th.

D.
You hit the soft limit of 2 VPCs per region and requested a 3rd.

Explanation:
There is a soft limit of 5 EIPs per Region for VPC on new accounts. The third environment could not allocate the 6th EIP.
http://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html#limits_vpc