Why RHELSA 7.1 doesn't have 'Development' environment in the software selection?

Hi There,

I try to install REHLSA 7.1 with development environment, but I can see the item in the installation source.
I try to install CentOS 7.1 (CentOS-7-x86_64-DVD-1503, similar to RHEL 7.1), there is a 'Development and Creative Work Station' item in the installation source.
Does any one know how to "active the 'Development' environment item" at the begining of installation?
To install all the rpm packages manually is pretty exhaustive and time consuming.

Thanks,
Ryan