An administrator is looking to apply a new service pack for an OS on several systems that run business critical applications for a large international finance corporation. 
Which of the following should the administrator do FIRST？（）

A. Deploy the service pack to a single department within the corporation. 
B. Upgrade the system with requirements for that service pack. 
C. Deploy the service pack to a non-critical application server. 
D. Submit a change control for the service pack deployment.