You need to configure Office 365

You are the Office 365 administrator for a company.
You must modify the configuration of the Office 365 tenant to allow users to instant message users only with
partner companies.
You need to configure Office 365.
What should you use?

A.
the Windows PowerShellSet-CsPersistentChatPolicycmdlet

B.
the Microsoft Exchange admin center

C.
the Office 365 SharePoint admin center

D.
the Windows PowerShellSet-CsExternalAccessPolicycmdlet