You work as an IT administrator in a large company, City Power and Light, which operates in an Active Directory environment. The company needs a PKI branch to authenticate its internal users, computers, network devices, and applications. It also plans to develop a relationship with an external business partner that requires an integrated and heightened joint security structure. Following best practices, what PKI systems should you deploy?

A. One offline root CA, one enterprise issuing CA, one policy CA, and its subordinate enterprise issuing CA B. One online root CA, one stand-alone issuing CA, one policy CA, and its subordinate stand-alone issuing CA C. One online root and issuing CA D. One offline root CA and one policy CA with two subordinate stand-alone issuing CAs