单选题The cisco ironport portfolio performs which service?（）A reduces the downtime that is asassocoated with spam,viruses,and blended threats that are delivered via emailB determines if A user or device is authorized to access A switch portC defends thepenme
题目
单选题
The cisco ironport portfolio performs which service?（）
A
reduces the downtime that is asassocoated with spam,viruses,and blended threats that are delivered via email
B
determines if A user or device is authorized to access A switch port
C
defends thepenmeter from malicious users and unauthorized traffic
D
providesA secure communication path through the internet