You work as the exchange administrator at Company.com.the Company.com network contains an exchange server 2010 organization.Company.com has its headquarters in stockholm where you are located.you are responsible for an exchange 2010 edge transport server named -ex01.during the course of the week you receive an instruction from the cio to make sure that e-mail messages sent to unknown addresses in the organization is rejected automatically.What should you do？（）

• A、You should consider configuring recipient filtering.
• B、You should consider configuring sender reputation.
• C、You should consider configuring content filtering.
• D、You should consider configuring sender filtering.