A customer asks the pSeries technical specialist to recommend which remote access （SSH or Telnet） method to use.  What question should the customer be asked to best determine the proper recommendation？（）

A.Is there a need for a PKI Management System？
B.Is there a need for end-to-end encryption？
C.Do they currently have a Kerberos domain in place？
D.Which clients are installed on their desktops -- SSH， Telnet or both？