You work as the exchange administrator at TestKing.com. The TestKing.com network contains anExchange Server 2010 Organization that contains a number of Hub Transport servers. During the course of day you receive an instruction form management to recommend a messaging hygiene solution. Your recommendation should ensure that servers known to send spam is blocked andthat the administrative efforts are reduced. What should you do？（）

• A、You should recommend to management recipient filtering.
• B、You should recommend to management an IP Block list.
• C、You should recommend to management IP Block list providers.
• D、You should recommend to management sender filtering.