What should you do to isolate development environments from staging and production?

A. Create a project for development and test and another for staging and production

B. Create a network for development and test and another for staging and production
C. Create one subnetwork for development and another for staging and production
D. Create one project for development, a second for staging and a third for production

References: https://cloud.google.com/appengine/docs/standard/go/creating-separate-dev-environments