单项选择题
A. set security policies from-zone dmz to-zone untrust policy anti-spam then permit application- services utm-policy Block-Spam
B. set security policies from-zone untrust to-zone dmz policy anti-spam then permit application- services utm-policy Block-Spam
C. set security policies from-zone untrust to-zone dmz policy anti-spam then permit application- services anti-spam-policy
D. set security policies from-zone untrust to-zone dmz policy anti-spam then permit application- services Block-Spam