Which of the following describes the BEST approach for deploying application patches?

Which of the following describes the BEST approach for deploying application patches?
A . Apply the patches to systems in a testing environment, then to systems in a staging environment, and finally to production systems.
B . Test the patches in a staging environment, develop against them in the development environment, and then apply them to the production systems
C . Test the patches in a test environment, apply them to the production systems, and then apply them to a staging environment.
D . Apply the patches to the production systems, apply them in a staging environment, and then test all of them in a testing environment.

Answer: D